Talk:Iron–hydrogen alloy

Stoichometry and fourth form

If I understood correctly, Antonov et al conjectures that one of the high pressure forms is FeH
_0.42 or so rather than FeH, and that there is a fourth metastable form. But I could find no confirmation of either. --Jorge Stolfi (talk) 18:06, 18 February 2013 (UTC)

Confusion

I am confused. Iron-hydrogen cannot be both an alloy and a chemical compound, iron hydride. Biscuittin (talk) 01:04, 30 November 2014 (UTC)

Who said that it is a chemical compound? Plasmic Physics (talk) 12:00, 30 November 2014 (UTC)

The first line in the article: "Iron–hydrogen alloy, also known as iron hydride". Iron hydride is a compound and has a fixed formula. Alloys have variable formulae. Biscuittin (talk) 16:42, 30 November 2014 (UTC)

The article you link to does not refer to a single compound as you suggest, and correctly states that the term has more than one meaning. In this usage, it refers to the alloy. Plasmic Physics (talk) 20:17, 30 November 2014 (UTC)

Accuracy dispute

Quote: "The hydrogen in typical iron hydride may contribute up to 0.001% of its weight". Iron(I) hydride contains 1.75% hydrogen and Iron(II) hydride contains 1.72% hydrogen. The author seems to be using Iron hydride as a synonym for Iron–hydrogen alloy when it is actually something completely different. Biscuittin (talk) 17:03, 30 November 2014 (UTC)

The reference I gave, exemplifies how 'iron hydride' is used to refer to the alloy. Plasmic Physics (talk) 20:19, 30 November 2014 (UTC)

The on-line reference only mentions Iron hydride. It does not say that Iron–hydrogen alloy is a synonym. Biscuittin (talk) 20:27, 30 November 2014 (UTC)

Even though, it is not explicitly using the term 'iron-hydrogen alloy', we already know that it is using 'iron hydride' to refer to the alloy. Plasmic Physics (talk) 22:11, 30 November 2014 (UTC)

How do we know? Biscuittin (talk) 22:43, 30 November 2014 (UTC)

It is called an alloy, and treated as such elsewhere. Plasmic Physics (talk) 22:54, 30 November 2014 (UTC)

Where? Biscuittin (talk) 23:02, 30 November 2014 (UTC)

I have amended the article, to remove the confusion. If you are happy with this, I think the accuracy dispute is settled. Biscuittin (talk) 10:14, 1 December 2014 (UTC)

First of all, the statement fragment "The term may refer to iron with a very low percentage of hydrogen..." repeats what is in the paragraph immediately following. The fragment "...absorbed in the molten state at ordinary pressures..." is incorrect in terms of its exclusivity - absorption is not limited to the molten state. Secondly, the high pressure forms are not compounds. Plasmic Physics (talk) 11:39, 1 December 2014 (UTC)

OK, I have changed "also known as iron hydride" to "sometimes known as iron hydride". Is this acceptable? My point is that Iron–hydrogen alloy and Iron hydride are not the same thing. Biscuittin (talk) 13:46, 1 December 2014 (UTC)

Why are you insisting that is the case, when there is an entire article that serves the sole purpose of saying that 'iron hydride' is in fact a synonym for iron-hydrogen alloy among several other meanings? Plasmic Physics (talk) 21:35, 1 December 2014 (UTC)

I'm not sure whether you are agreeing with me or disagreeing with me. Could you please try to clarify your last statement. Biscuittin (talk) 00:59, 2 December 2014 (UTC)

I'm saying that I'm frustrated with my inability to correct your understanding of the term 'iron hydride'. I'm saying the page Iron hydride is a set index article, describing the different usages of the term, including as this alloy. I can't figure out whether you're just ignoring it, or haven't bothered to actually read through the article. Plasmic Physics (talk) 01:47, 2 December 2014 (UTC)

Have you resolved this dispute or do you still need a third party to look over the situation? Tarnas (talk) 05:23, 2 December 2014 (UTC)

Yes please, we do need a third party. User:Plasmic Physics and I seem to be totally unable to understand each other. Biscuittin (talk) 09:43, 2 December 2014 (UTC)

I have restored the article to the version by Plasmic Physics dated 1 Dec 2014 and added a top link for clarification. However, I still think the article is misleading because it uses the terms "Iron–hydrogen alloy" and "Iron hydride" as if they were interchangeable. It may be that physicists call Iron–hydrogen alloy Iron hydride but, to a chemist, this is wrong because one is an alloy and the other is a chemical compound. Biscuittin (talk) 13:48, 2 December 2014 (UTC)

I reject the idea that Iron hydride is a set index article. A set index article (e.g. Copper oxide) is just a list. Iron hydride is an article with references. Biscuittin (talk) 14:03, 2 December 2014 (UTC)

Perhaps I am out of date. I have just read Interstitial compound and it seems that a compound can be an alloy. Biscuittin (talk) 14:12, 2 December 2014 (UTC)

I see that User:Plasmic Physics has edited Iron hydride to match his point of view without giving a reference. Biscuittin (talk) 14:22, 2 December 2014 (UTC)

It does not matter if it's right to a physicist and wrong to a chemist, Wikipedia is for everybody. There is no credible reason to discriminate against an established synonym other than practical ones. A set index article is more than just a list copper oxide is a poor example. The prime example given in the article which directed you to, is Dodge Charger. The reason for the expanded definition in iron hydride, is to take account of the definition of the difference between compounds and mixtures as stated in Chemical compound#Compounds compared to mixtures Plasmic Physics (talk) 01:32, 3 December 2014 (UTC)

I've reviewed your situation and the related topics. I'll be back in a few hours to start the discussion and give you my perspective. Tarnas (talk) 21:38, 2 December 2014 (UTC)

From what I can tell, there are two major things going on here. (#1) User:Plasmic Physics is a domain specialist who contributes a lot of content to a variety of articles, but he does not appear to be particularly good at citing sources for his contributions. This is problematic because, though what he writes appears to be correct, without a source no one can check. However, since this is a low priority chemistry page dealing with an esoteric subject, I would err on the side of leaving User:Plasmic Physics's contributions. User:Plasmic Physics, it would help if you could be more diligent in citing sources. If you are inspired to expand articles rapidly in the way that appears to be your M.O. based on your contribution history, you should perhaps create drafts beforehand and carefully find citations to your statements. This is time-consuming work but wikipedia users in the years ahead will be thankful, and there's no other way to ensure that all your work stays put unless it's cited. Other users can leave uncited scientific material in an article only so long before someone needs to find a citation or delete it.

(#2) The beginning of this dispute, however, is a much more narrow question: the difference between alloys and compounds. In the case of metal solutions with less massive elements like hydrogen, there is no clear line between mixtures, alloys, and compounds. This is not the neat world of chemistry that we were perhaps taught in school. It is now very much the domain of specialists. It appears that chemists are themselves rather lax in using the term "alloy". Perhaps a more accurate approach for defining these substances is to refer to "phases". Here are some related documents on the subject:

• Phase_(matter)
• Solid_solution
• Bonding_in_solids
• Metallic_bonding
• Intermetallic
• Transition_metal_hydride
• Non-stoichiometric_compound

If I had lots of time to deal with this, I would probably recommend merging Iron–hydrogen_alloy with Iron hydride and giving every phase, compound, alloy, or whatever you want to call it of the iron-hydrogen system its own due treatment. It would probably be best to create a single chart of all possible iron-hydrogen systems, with phase diagrams, and give any secondary technical names for specific phases, so that all of them can be seen in one place. I am not going to do this though, and I would recommend simply noting in this article that there is no strict definition of the term "alloy" in the context of metal hydrides; that it may be more for historical reference purposes that the nomenclature persists; and ideally we would find a discussion of this issue in a citable textbook, chemical naming specification, or other source, and use that to inform this article. But really the overlap between alloys, compounds, solid solutions, phases etc is a larger problem in this area of chemistry and physics and won't be solved in this minor article. User:Biscuittin, it appears that if you want clarity, you will also have to go to the scientific literature and find a discussion of the use of the term "alloy" among metal hydrides, and distil that discussion for wikipedia.

I'm not sure where that leaves us but I'll stop writing now and see what you each have to say.Tarnas (talk) 03:54, 3 December 2014 (UTC)

Editing proposal

Nearly all the contributions from User:Plasmic Physics have been unreferenced and, in some cases, inaccurate. As an example of inaccuracy I give this: "Iron is extracted from iron ore by removing the oxygen through combination with a preferred chemical partner, such as hydrogen that is lost to the atmosphere as water". Unless I am much mistaken, the usual way to extract iron is by reducing iron ore with carbon, see Iron_ore#Smelting. Because of this, I intend to restore Iron–hydrogen alloy to the version of 31 August 2014 by 88.104.104.115. I am putting this up for discussion before I do it. Biscuittin (talk) 20:47, 2 December 2014 (UTC)

I would recommend waiting for a few days until we consider the pending dispute above. It's quite possible that User:Plasmic Physics is contributing useful information but is not good at citing sources, and this wikipedia article is of low enough priority that there is no need to revert it immediately. Tarnas (talk) 21:36, 2 December 2014 (UTC)

OK. Biscuittin (talk) 23:07, 2 December 2014 (UTC)

The sentence makes no indication whatsoever that the extraction process is the preferred method. Plasmic Physics (talk) 01:41, 3 December 2014 (UTC)

Earlier I disagreed with Plasmic about calling solid hydride compounds "alloys". There seemed to be original research and undue pushing of the term. He did find one reference that suggested the use alloy, but primarily "alloy" was not used. The original article called iron hydride that I wrote was about all the different iron hydrides, including the molecules, the high pressure phases, (with different crystal structure) and the low pressure, low hydrogen composition substance (that last could be termed an alloy as it had the same crystal structure as pure iron). Graeme Bartlett (talk) 01:27, 3 December 2014 (UTC)

Who says that is a requirement for any alloy? Plasmic Physics (talk) 01:41, 3 December 2014 (UTC)

At least three sources referring to it explicitly as an alloy: [1],[2], [3]. Plasmic Physics (talk) 01:50, 3 December 2014 (UTC)

I am saying that we had an argument about it. But I have not said what I think needs to be changed. This article is about solid or liquid iron hydride. It is not a set index, but a stlightly more general article documenting condensed forms. It is rarely called an alloy, and very seldomly called "iron hydrogen alloy". But that is not what the dispute is about. Most of the content here is what I originally wrote, but what is different is the lede and the section on the low % H alloy. Graeme Bartlett (talk) 03:14, 3 December 2014 (UTC)

Looking at the references above, the first I can't tell, the second uses the term "iron hydride", but the last does use the term "iron hydrogen alloy" with no dash or hyphen. So nothing matches the current article title. Graeme Bartlett (talk) 03:20, 3 December 2014 (UTC)