Talk:Boron nitride

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Good article Boron nitride has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
July 6, 2009 Good article nominee Listed
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disputed[edit]

There are several compounds harder than cubic boron nitride, most of which are nanocomposites. lysdexia 04:46, 24 Nov 2004 (UTC)

Graphite-like, diamond-like[edit]

I'd rather call it hexagonal and cubic. Maybe leave graphite-like as a remark, but the 'diamond-like' phase is cubic (contary to tetrahedal bonded diamond). Also in the Material-properties template under appearance the two modifications should be mentioned. --Dschwen 07:16, 12 Jan 2005 (UTC)

"Diamond cubic" is the name of the crystaline structure of most semiconductors, including diamond, BN, and SiC, and Si. Yes, the bonding is tetrahedral; in fact, tetrahedral symmetry is only found in cubic systems (look down the corner of a cube if you don't see the 3-fold axis at first).--Polyparadigm 23:27, 13 Feb 2005 (UTC)


Crystal structure[edit]

I find the use of the terms cubic and hexagonal ambiguous when applied to the carbon allotropes. Cubic close packing (ccp) and hexagonal close packing (hcp) are crystal structures derived from the closest packing of spheres to maximise space usage (74%). Diamond is composed of two interpenetrating ccp lattices. Graphite is not a close packed structure. However, graphite is composed of layers of fused hexagonal sheets.

"Ingestion" changes[edit]

I noticed a "not hazardous" note next to the "Ingestion" label in the table, and deleted it, assuming this referred to transportation regulations or something else. After a brief search of the web, I was not able to reach a definitive conclusion with regard to safety, as the web pages I looked at seemed to be somewhat contradictory. Perhaps someone with experience and knowledge on the safety of boron nitride can update this appropriately. Does anyone know what the "not hazardous" note refers to?--GregRM 18:53, 2 May 2006 (UTC)

It's chemically inert, at least the diamond- and graphite-like allotropes, so it's non-toxic. The fullerene-like allotrope might be bad for you, though. —Keenan Pepper 19:30, 2 May 2006 (UTC)
If you're really interested, google "boron nitride MSDS". Most of them either say "no effects" or at worst "irritant", which just means it's an abrasive. —Keenan Pepper 19:34, 2 May 2006 (UTC)

Comparison with recent borides?[edit]

Should we list other ultrahard boride compounds in "See Also"? Apparently Rhenium Diboride and Boron Aluminum Magnesium (BAM) Materials rank highly. Not sure if BAM is the preferred term. Does anyone have a broader perspective? —Ahazred8 07:45, 21 April 2007 (UTC)

h-BN sheets not quite planar?[edit]

I made the crystal structure images that appear in this article, but recently I heard that hexagonal boron nitride (h-BN, graphite-like) is not entirely planar, despite most textbooks and all the structural papers I could find (e.g. Pease) saying it is planar.

Does anyone know of a more recent structural determination with pyramidal nitrogens?

Ben (talk) 19:29, 28 March 2008 (UTC)

BN has attracted recently a good deal of attention as being similar to graphene i.e. existing in (almost) two-dimensional structures: Appl. Phys. Lett. 92 (2008) Issue 13, id. 133107.195.96.229.83 (talk) 11:40, 1 July 2008 (UTC)

BN gem?[edit]

Why isn't this chemical used as a Diamond_simulant? Since learning about the atomic structure of this in school long ago, I thought it would be really cool to have a boron nitride ring rather than a diamond one. —Preceding unsigned comment added by 141.243.60.12 (talk) 01:02, 30 April 2008 (UTC)

Tables are over the text[edit]

Is it my computer or is there something wrong with this site? The text is hidden under the tables and charts. Help!!!69.122.62.231 (talk) 21:32, 20 May 2009 (UTC)

GA Review[edit]

This review is transcluded from Talk:Boron nitride/GA1. The edit link for this section can be used to add comments to the review.

I will be happy to review this article. Diderot's dreams (talk) 04:34, 17 June 2009 (UTC)

None of the quick-fail criteria apply and the article will get a full review. I have given the article a copyedit for grammar, spelling, and punctuation errors. There were many missing articles (the, a). Some of this may be due to differences in my American usage and U.K. usage. If so, well it doesn't hurt anything to add the article. Still there were a lot of mistakes even assuming some of the article omissions were just regional preferences. I am guessing the main author is not a native English speaker. Having someone (from the League of Copyeditors, maybe?) go over the article before submitting is a good idea.

Straigtforward fixes I've taken care of; there are some more complex grammar and usage issues (involving meaning) I'll bring up in the review.

Also, the tables were leaving a small gap for text to go through on my browser. I am using a common desktop setup, so I bet this is a widespread problem. I've forced the text to not flow next to the table. Diderot's dreams (talk) 07:11, 17 June 2009 (UTC)

Review[edit]

The article covers BN in an engaging and structured fashion. It addresses the various BN forms, a critical aspect of the chemical. Edifying analogies to carbon are brought out and applications of the compounds are explored. Relevant and informative images and illustrations are used. Many relevent physical properties have been listed. There were many mistakes in English usage, but I'd like to add that the article wasn't overly encumbered by them.

The article is obviously written by people who have specialized knowledge. Readers who have training in the physical sciences will understand the article. It is clear that the article's contributors like their topic (and there are a few enthusiastic sentences that need specific citations if we want to say them). Other than this, the article is well referenced.

So there's a lot of Good, but there's also a fair amount of the Bad and the Ugly:

Clearly Written

Like many technical topics, the article is somewhat overwritten for the general reader, with too much unexplaned jargon as well as using complex words and structures where simpler ones would work. Because of the variety of heterogenous compounds BN forms, the article neccessarily utilizes many varied technical concepts. Explaining all of these to the general reader is hopeless, and we need to keep the information for the specialist. However, some of the more central ideas and general principles can be explained for our general readers. And without losing meaning. With this in mind:

  • (Done) Can we please explain, or eliminate by using simpler wording that defines them, the following chemistry terms for the ordinary reader? We can assume the reader knows basic chemistry ideas like atom, bond, or energy.
(ok) binary chemical compound
(ok) isoelectronic
(ok) polymorph/polymorphic forms/allotrope
(ok) Van der Waal's bonds (forces?)
(ok) sintered
(ok) nanotube
anisotropy
(ok) intercalated
fiber (chemically speaking)
(ok) amorphous
(ok) metastable
(ok) wetting (chemically speaking)

I have clarified or avoided using some of those terms, except for: Van der Waals forces (explaining it would go to far from the topic, that is why wikilinks), anisotropy (already explained in the follow-up sentence), fiber and wetting (sorry, I didn't understand "chemically speaking" - those words are used in their basic, primitive meanings in this article). Materialscientist (talk) 05:50, 26 June 2009 (UTC)

Everything that has an (ok) or crossed out are good with me. I can let 'Van der Waals forces' go. As for 'anisotropy', it's not exactly defined, but the following examples give a strong indication of its meaning, and there's a wikilink. I think with 'metastable', you've lost information along with the term. A major point, in fact, but for GA you are allowed to miss a few. Still it would be better to have the information. 'Sintered' hasn't been addressed yet.
I simply forgot to type in changes on sintering. Fixed now. The trick with sintering is that it is a special phenomenon, which is not really fusing, but "fusing" is very close in meaning. "Metastable" I did not forget, but .. while re-reviewing the literature yesterday, I came to that whether c-BN or h-BN is more stable is being contensted by one very strong and respectable research group. There is no dispute that c-BN is obtained from h-BN, but there is a doubt that c-BN has higher total energy. Thus it is more like "non-equilibrium" or "dynamic" than "metastable" Materialscientist (talk) 03:51, 27 June 2009 (UTC)
It wouldn't hurt to add the information in the form of a controversy. Though this seems a minor point. As for sintering, can we can describe it as a type or variation of fusing? Now it seems like it's just a synonym. Diderot's dreams (talk) 16:44, 27 June 2009 (UTC)
Hm.. I was just involved in one on WP. It is tricky - we may only bring up controversies on WP if third parties acknowledged they existed. Here, I see a controversy behind the text of a certain article, but no-one else apparently noticed that :) Anyway, it is indeed a minor issue Materialscientist (talk) 00:27, 28 June 2009 (UTC)
By "chemically speaking", I meant a couple of things. For fiber, I meant what is going on a the intermolecular level. By describing it as analogous to a carbon fiber and wikilinking, you'd already made a way for the reader to figure that out. As for wetting, I was worried wetting as used in the article might be in some way different from the everyday phenomenon. It might be good to say that it is the same as the ordinary phenomenon by using a footnote. Diderot's dreams (talk) 01:38, 27 June 2009 (UTC)
I would not confuse the reader by saying that wetting is meant in usual sense, because I don't know another one, and the reader might start thinking "is there another one ?" :) Materialscientist (talk) 03:51, 27 June 2009 (UTC)
I think that is what the reader would do now. And we can add to the footnote that there isn't another sense. Diderot's dreams (talk) 16:44, 27 June 2009 (UTC)
Added a note. Materialscientist (talk) 00:27, 28 June 2009 (UTC)
  • (Done) The following can be reworded in plainer English (suggestions in parentheses):
(ok) "ambient conditions" (room temperature)
(ok) "normal" (perpendicular)
(ok) "results in" (causes)
(ok) "diminished" (reduced)
(ok) "basal plane" (plane?)
(ok) "deep UV light" (UV light near the ??? spectrum)
(ok) "light emitting diodes" (LEDs)
(ok) "used as BN etchants" (etch BN, change to active tense)
Reworded, except for one occurrence of "results in", "LEDs" (sorry, abbreviations must be defined) and "basal" (handy word, which I explained in the revised version; you can't just say planes because they may cross a solid in any way), Materialscientist (talk) 05:50, 26 June 2009 (UTC)
Good progress. Where terms are explained rather than changed also. I'm glad to see you added LED in parenthesis, everyone understands that. The etching rewording issue is the only one left. It isn't gramatically correct as it is now. We could say "which can therefore etch BN.", but I think "which can be used to etch BN." or "which are used to etch BN." are better choices and what I was trying to get at. Diderot's dreams (talk) 02:02, 27 June 2009 (UTC)
I changed the etching part. Materialscientist (talk) 03:51, 27 June 2009 (UTC)
  • (Done) Also, can we better explain for the general reader that different solid structures of the same molecule exist and have different properties.
    Could you please be more specific ? I do not think we need to repeat banalities that carbon can be (soft black) graphite and (hard clear) diamond. Its even in oscar-winning holywood movies :). Materialscientist (talk) 05:50, 26 June 2009 (UTC)
An explicit explanation seems unnecessary to me now with the new revised text. Not sure exactly why, things being better organized and explained may have something to do with it.(?)
  • (Done) Hexagonal boron nitride is produced by the nitridation or ammonolysis of boron trioxide or boric acid; for example, treatment of boron trioxide with ammonia or of boric acid or borate salts with urea, guanidine, melamin or other suitable organic nitrogen compounds in nitrogen atmosphere. This sentence is just too long makes it hard to understand.
    Reformulated. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) lead: '(Mohs hardness ~ 2)' This detail we can save for later.
    Deleted there. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) lead: 'The cubic zinc blende variety (c-BN)' is there zinc in it? I think this description is confusing, maybe say 'c-bc, a 2 elemental mix like a zinc blende,' would explain things better
    Rephrased. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) Does the wurtzite polymorph have a greek letter prefix?
    Not that I know. For BN, even alpha and beta are obsolete and much less used than h-BN and c-BN. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) It would be better if the nanomesh section went before the nanotube section.
    Moved. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) Amorphous boron nitride needs a mention in the structure section, as it is a basic BN form.
    Mentioned. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) due to 10B's neutron absorption properties Let's use the active tense 'because 10b absorbs neutrons'.
    Yes. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) The picture of BN in the infobox needs a caption that describes which form we are seeing (the hexagonal, I presume).
    Yes, its h-BN. The template is programmed such that image name is only seen when you point a mouse to it. c-BN looks very similar. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
That's not really a caption. I think we need a real caption with the specific form named.
I tried to hack the template, failed, and finally just edited the figure. One can reprogram the core template, but its risky as hundreds of articles use it.Materialscientist (talk) 03:59, 29 June 2009 (UTC)
Those templates don't always cooperate with GA requirements. The last article I reviewed had a template with a numerical parameter that wouldn't accept a citation. Had to add it to the article text. Diderot's dreams (talk) 14:02, 29 June 2009 (UTC)

Breadth (addressing all main aspects and most major points)

  • (Done) BN is not naturally occuring and this needs to be in the article.
    Added on top of the "synthesis". Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) While the microstructures of BN are described, the ordinary appearance of the forms have not been described, e.g. a plain white powder, a translucent crystal, or whatever happens to be the case.
    This information is in the chembox. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
I see you've added the info for the crystals. The information does work well there, since the article concentrates on the structure and macroappearance seems a bit of a diversion. But lets specify which appearance is for which forms, to make things "crystal clear" for the reader. Diderot's dreams (talk) 04:30, 28 June 2009 (UTC)
I clarified that. Materialscientist (talk) 03:59, 29 June 2009 (UTC)
That helps, but we need to specify that the white powder is the amorphous form. This is right, yes? This wording might work: translucent crystals (c-BN, h-BN); white powder (amorphous BN)
  • (Done) We haven't talked about industrial production-- I mean where and how much? And perhaps it's precursor, boric acid, where is it obtained from?
    Added on top of the "synthesis". Materialscientist (talk) 05:50, 26 June 2009 (UTC)
Here we need to move the article out of the world of chemistry and material science into the real world. Information on BN's commercial production is what is missing. Where is BN produced? Is it made up at the site that uses it (like a cosmetic factory) or somewhere else? How many tonnes are produced per year? What countries are the leading producers? This is a main aspect that has to be addressed. By "addressed" I don't mean completely, but talk about it in some way. Like answering a some of the questions above.)
Added some. The trick is that official sources do not split up fractions of BN production out of other boron compounds; BN fraction is small, and everybody speculates. I chose a "respectable speculation" from a peer-reviewed journal. Materialscientist (talk) 03:59, 29 June 2009 (UTC)
  • Isn't hexagonal boron nitride aromatic? I think that should be stated and that causes the planarity and at least contributes to its stability.
This could be a long discussion between a chemist and physicist, but the short answer is no - neither graphite nor h-BN are considered "aromatic" in the literature. The planarity of inorganic crystals has many other reasons, and some related compounds (e.g. metal borides) are actually non-planar. As I understand it, in graphite, we've got a zero bandgap, i.e. the 4th electron from every carbon atom is smeared all over the graphite plane (this is not like benzole rings). In h-BN, those extra electrons are localized at the lone pair of nitrogen. That's why no conductivity and no delocalization. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
I'll try to be brief :).
Graphite is aromatic, and is described so [1]. It is an increasing structure of fused benzene rings. Starting with benzene, everytime you add another bensene ring to the structure, aromaticity is preserved and the aromatic MOs spread throughout all the rings, and the band gap drops. And so this goes out to inifinity, and the band gap approaches zero. It is because of the aromatic character of graphite that the band gap is zero in graphite and the electrons are free to go throughout the structure.
When dealing with different elements, p-orbital overlap becomes poorer and we have less hybridization and less delocalization. The aromatic character becomes imperfect, and we have less aromatic character, some polar character and some resistivity.
Here is an interesting examination of h-BN and whether it's aromatic. [2] The author seems to be saying that h-BN is a polar "ionic" aromatic compound. Thoughts? Diderot's dreams (talk) 15:21, 29 June 2009 (UTC)
Thanks, you know this topic better than I do. When I was looking for aromaticity in graphene, I found another article at acs.org, which used the same arguments to say that graphene is not aromatic, namely because of its zero gap, all aromatic effects have been "washed out" by the infinity of the structure. I am happy to admit I'm wrong. I just felt this is all about who interprets the facts :) Why I said it is not - I searched for "graphite + aromatic" and got very few results, whereas I should have used "graphe* + aromati*". For h-BN its trickier. Reading the reference you provided, it becomes clear that the author is speculating. I have to disagree that NMR is a proof here, but I do agree that BN is ionic, no doubt about it. I also disagree with the right picture in that reference. Why ? I was seriously involved in studying substitutional nitrogen in diamond (with vacancies around or without; EPR + theory + optics), and there, the nitrogen does everything to keep a "lone pair", i.e. 3 electrons backbonded (all bonds almost in one plane) and 2 sticking out perpendicular to it. I believe same should happen here: nitrogen bonded to 3 borons and a lone pair sticking out of the plane. Again, I am happy if someone shows me otherwise. Materialscientist (talk) 03:21, 30 June 2009 (UTC)
The author does say that others have concluded that h-BN isn't aromatic, so we don't have a consensus amongst scientists, and the controversy is a minor point. That said, I'll think some about what you're saying and get back to you. Diderot's dreams (talk) 05:33, 1 July 2009 (UTC)
I think you've done a good job of summarizing it.
  • (Done) The phases BN exists in and under what conditions (temperature and pressure) have not been specifically described. We should say a little about gaseous BN. Why BN sublimates would be a nice addition too.
The P-T conditions for conversion between h-BN and c-BN are mentioned in "Preparation of cubic BN". I added on sublimation of BN (end of physical properties). I do not understand the question why BN sublimates. All solids do, its just a matter of pressure. Very few experiments on BN indicate that BN sublimates at normal pressure, but melts at elevated pressure. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
My interest was why BN sublimates at standard pressure-- is so susceptible to it. I don't have a clear reason, sublimation is explained as a matter of equilibrium vapor pressure. BN for whatever reason has a high equilibrium vapor pressure. I suppose there's something about the liquid state that just isn't very energetically favorable. Anyway, there's nothing definite here.
  • (Done) Physical properties of amorphous BN need to be added to the appropriate table, if they have been characterized.
    Added what I could. Those are hard to find. Materialscientist (talk) 05:50, 26 June 2009 (UTC)

Accuracy

  • (Done) in the structure section- it says that both the cubic and hexangonal forms are called alpha-BN. Isn't this wrong?
    Typo. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) 'Van der Waals bonds' Don't we really mean Van der Waals forces? They aren't really bonds-- with the requisite strength and permanance.
    Changed to forces. (there is a big difference between forces and bonds, but it is not essential there). Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) Several allotropes of boron nitride are known. This seems to think that they have to be discovered in nature. 'have been created' would probably be more accurate.
    Yes. Changed. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) In the "Reactivity of BN with solids" table, I think we are talking about c-BN, as other forms will have different reactivities.
    Yes, its c-BN, but its not much different for h-BN (for the few chemicals where cross information exists). Materialscientist (talk) 05:50, 26 June 2009 (UTC)
You might put the article text in front to emphasize the similiarity. Or say something about it in the text.
Yes, added and moved. Materialscientist (talk) 03:59, 29 June 2009 (UTC)

Other (POV?, references, organization)

  • (Done) Please provide specific citations for the enthusiastic statements I've marked with fact tags.
    Provided. Materialscientist (talk) 05:50, 26 June 2009 (UTC)
  • (Done) The nanomesh section belongs in front of the nanotube section.
    Moved. Thank you for careful reading ! Materialscientist (talk) 05:50, 26 June 2009 (UTC)


Well that's quite a bit and should be most if not all of the article's shortcomings. I may find a few more later. I haven't talked about the lead, there's some stuff that needs adding to the article first. It looks good, certainly no major issues.

So the article is On Hold so improvements can be made. I will use (Done) in front of my comments to indicate that something is, well, done. I'd appreciate if you don't use that or any graphics to indicate you've completed something. A few words under the issue like a further comment work well. Other brief comments by anyone can go there too. Please put extended comments in a separate subsection after the review. I'll look in on things frequently while the article is on hold. Thanks, and thanks for your contribution to the encyclopedia. Diderot's dreams (talk) 09:59, 25 June 2009 (UTC)

I've looked at and updated many of the simpler items and made a few comments. I haven't checked everything yet, I'll get to the rest tomorrow as I'm feeling a bit under the weather. So if there's nothing said about a point, it doesn't mean it's still an issue. Overall, I like the revised article :). Diderot's dreams (talk) 02:26, 27 June 2009 (UTC)

More Review[edit]

I am enthusiastic about the improvements. But on a second reading, the article is still not ready. I don't like to make another list, but I'm seeing what I'm seeing. Here are the things that still need improvement, (they are generally less involved):

  • (Done) lead: For summarizing, I think we need to work in these ideas: h-BN used in cosmetics, BN is synthetic, something about production.
Added. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
The new information is well integrated.
  • (Done) lead: When boron and nitrogen atoms are bonded together they have a similar electronic structure to carbon How about "an electronic arrangement similiar to the corresponding carbon structure" instead. I think that hits the nail on the head.
Considering our discussion above, I proposed a more careful interpretation. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
Good point.
  • (Done) Physical properties table: the title needs cleanup as it is too long. Instead of listing all the forms, I suggest "Forms of BN and Carbon". The "Some properties..." part is not really part of the title, so we should do something with it. And let's adjust the column widths so all the column headings are single line.
I reduced the title, but am afraid to cut more as we shall lose crucial information. On my PCs (vista/XP + firefox) all column headings have single line. This could be autoformatting by a browser. Can't fix that without seeing the problem. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
I am thinking that the difference is screen resolution, rather than browser or operating system. I use 1024x768 which is still common. I suppose you are using a wide screen monitor or a laptop at a resolution that is wider, so the table has more room.
I use a laptop with 1024x768 and a desktop with 1280x1024, which I thought gives me some some sort of testing, but the previous referee reports suggested that some use lower and higher resolutions. You might have noted that I've set tables with text flowing over, and it seemed fine on my PCs, but perhaps not on yours (and someone else complained on garbled view on the talk page). More to this point, a third PC I sometimes use does not take more than one column (in refs or other lists) and puts them into one. I think WP layout is never ideal, and that WP programmers know much more about that. Materialscientist (talk) 00:26, 2 July 2009 (UTC)
We can leave the column widths alone, then. It seems that the tech guys might want to improve the layout engine. Spelling out the forms in the title reads more like a scientific journal rather than an encyclopedia to me. The cites in the middle of it make it more "technically". It's seems a little too much for non-science people. Also, the statement about the anisotropic properties needs to be differentiated from the title. For example, in parentheses on a separate line below the title. It reads like it's part of the title now.
I moved the anisotropic properties into footnotes, but can't tear the rest - references are absolutely necessary for such tables. Materialscientist (talk) 06:15, 3 July 2009 (UTC)
[outdent] First, let me explain why I didn't respond sooner as I have been. My computer is having trouble (I am doing this post from a public terminal as was my last post) That was compounded by the 4th of July holiday here in the United States. Please don't interpret that as any interpretation of your comments or work.
As for the references, my intention was that they be moved elsewhere in the table. By this, I am thinking either (1) into the column headings, or better, (2) into italic text at the bottom of the table. It might read like this:
sources: amorphous BN[3][4][5], crystaline BN[6][7], ...
The title is good now, thanks. My other point was the anisotropy text, which I would suggest belongs right below the table title, (unbolded and maybe in italic) and not in a footnote, which seems to have complicated the table more and bury an important explanation. Diderot's dreams (talk) 02:20, 6 July 2009 (UTC)
I am actually more worried about your PC (i.e. you being disconnected from internet and WP) than this review. I have quick fixed the table. Materialscientist (talk) 03:30, 6 July 2009 (UTC)
The table looks good now. Diderot's dreams (talk) 18:33, 6 July 2009 (UTC)
  • (Done) Under Properties, we talk about that h-BN is warped, but it isn't talked about under structure.
Good point. I guess it was an error. What I've done with that is downloaded h-BN structure files from our structure database (it is an access to international one), drew the structure, and found no warping. Then searched for warped boron nitride on google and found no real proof. Then replaced warped with partly ionic in the text. Some other h-BN structures in the text are by Ben, whom I know as rather meticulous in this regard, and who uses other databases. He again plots no warping. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
  • (Done) Application of voltage to h-BN [12][13] or c-BN,[14] then they emit UV light in the range 215-250 nm and therefore can potentially be used as light emitting diodes (LEDs) or lasers. This sentence is gramatically incorrect: "Application of voltage" is the problem.
Fixed. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
  • (Done) The article says that BN is stable to certain temperatures under certain conditions. What does it become? (amorphous BN?)
Stable to decomposition. Added. Term stable is loosely and widely used in scientific literature without giving details (I know, sloppy). Materialscientist (talk) 07:40, 1 July 2009 (UTC)
  • (Done) Synthesis: we need to prepare the reader for the subsections. Some kind of sentence saying we are going to talk about the different preparations of BN. The problem is that the text "jumps" here:
Boron trioxide is obtained by heating boric acid.[18]
Boron nitride production and consumptions figures are not listed in statistical reports. An estimate...
Added a transition. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
Not what I meant. The synthesis text goes 1) BN is synthetic 2) this is how the precursors are made 3) here's how much BN is produced. After #2, the obvious thing the reader is expecting is how BN is synthesized from the precursors. Of course we want to put how BN is synthesized in separate subsections later because it's treated in great detail. But the lack of anything between #2 and #3 is jarring. So adding something like "How BN is synthesized is discussed below." Or some better way, my suggestion is a little awkward. Diderot's dreams (talk) 16:36, 1 July 2009 (UTC)
As a possible solution, I simply moved 3) to the bottom of production section. Materialscientist (talk) 00:26, 2 July 2009 (UTC)
  • (Done) If desired, the remaining B2O3 can be evaporated... The "if desired" sounds like it's from an instruction manual.
Absolutely redundant there. Deleted. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
  • (Done) Applications, Hexagonal BN: there are two one sentence paragraphs. We need to merge these in whatever way works.
Merged. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
  • (Done) Picture caption: "STM". Let's spell the abreviation out, people have a good chance of understanding that.
Spelled out. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
  • (Done) Several of the pictures thumbnails are smaller than are typical for a Wikipedia article. They are large enough to make out the picture, but I'd enlarge them some for consistency, aesthetics, and to make more room for the captions.
Policy issue. I avoid specifying pixel size everywhere unless letters are too small in the figure. This issue was raised in my previous GA reviews by referees having non-standard screen settings (they get poor page setup, whereas without px size the browser sets it up fine). Please feel free to resize whatever image. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
I tried this out with the pics that could use it; for various reasons it doesn't seem to work well to expand most of them. One won't expand at all as it's at its actual size. The ones in parallel shouldn't be expanded as they cover a good deal of width already. I did expand the intercalated pic a bit. I think this looks better, even at 800x600 that shouldn't take up too much room. Diderot's dreams (talk) 05:42, 3 July 2009 (UTC)
  • (Done) Applications: The amorphous boron nitride subsection belongs in the main section, not in "Other forms", since it is a basic form.
Sure. Moved. Materialscientist (talk) 07:40, 1 July 2009 (UTC)
  • (Done) Lastly, we still haven't explained sintering. I think we can say more than that it is just fusing.
I wouldn't explain it in the lead, but I added a bit on that in c-BN applications, where it first appears. The lead contains a link to sintering. Materialscientist (talk) 07:40, 1 July 2009 (UTC)

That's it! And don't worry about the 7 day deadline. Like most reviewers, I am willing to go up to two weeks for an article of this complexity. Diderot's dreams (talk) 05:33, 1 July 2009 (UTC)

I don't (I have one review going on for months already - unfinished FA) Materialscientist (talk) 07:40, 1 July 2009 (UTC)

Final Evaluation[edit]

That takes care of my last concern I'll raise for GA. I'm passing it as a Good Article. I have two more concerns, but they're not that big a deal. More numerical detail has snuck into the lead than probably belongs, and the note in the solid reactivity table probably ought to be one of those a,b,c internal notes like you had in the other table. I've changed the "References" section to "Notes and References" according to the layout guidelines. Change it back, of course, if you make the changes I'm suggesting.

So congratulations to Materialscientist and all others who contributed to the article. I'm sure the 100,000+ people a year who read this article will benefit from all your efforts. Diderot's dreams (talk) 18:57, 6 July 2009 (UTC)

c-BN harder than aggregated diamond nanorod?[edit]

On Talk:Aggregated diamond nanorod there is given information that c-BN could possibly be harder than aggregated diamond nanorod, which is considered the hardest substance on earth. Something on this should be mentioned here. __meco (talk) 19:46, 17 January 2010 (UTC)

Sure, when it becomes reliable :-) Seriously, many people are fascinated to find a breaking news, a material harder than diamond, and some of those went as far as Science journal and alike, but none are confirmed, as far as I know. Materialscientist (talk) 00:29, 18 January 2010 (UTC)

Recentism[edit]

The article is still mainly supported by a collection of recent journal articles, which is unfortunate.--Smokefoot (talk) 12:49, 1 November 2010 (UTC)

Natural occurrence of c-BN, qingsongite?[edit]

A recent Science News brief report (https://www.sciencenews.org/article/qingsongite) covered the identification and naming acceptance of natural c-BN, as "qingsongite" (/CHING-song-ite/), found in chromium rich Tibetan rocks. The IMA acceptance apparently happened back in August, with the original discovery cited as "Matzel, J. et al. 2010. Nanosims studies of ∂ 15N and ∂ 13C in nitrides inclusions in coesite from a Tibetan massive cromitite ore. Geochimica et Cosmochimica Acta, 74, 12, Suppl. 1, 680 p.; doi: 10.1016/j.gca.2010.04.039". Is this sufficient to change the introductory "Boron nitride is not found in nature" statement, or at least qualify it with an endnote?Kelseymh (talk) 05:14, 4 November 2013 (UTC)

I went bold and added, thanks. Materialscientist (talk) 04:08, 15 November 2013 (UTC)

What's the boiling point???[edit]

It's not listed. StainlessSteelScorpion (talk) 03:38, 15 November 2013 (UTC)

and is probably unknown - BN decomposes upon heating, that is, sort of sublimates. See "Thermal stability" section. Materialscientist (talk) 03:44, 15 November 2013 (UTC)