Talk:Material properties of diamond

Some questions

First, is there are reason Mechanical properties aren't included in this page. E.g. Compressive Strength / Tensile strength? If not it would be nice to see them added.

Second, will someone please fix or remove the link on the ballas diamonds, it currently takes you straight to Grand Theft Auto. --64.216.141.135 20:40, 1 November 2005 (UTC)

Hardest naturally occurring mineral?

I may be wrong, but is buckminsterfullerene not harder than diamond...?

It would help if you could provide a source.

In general, the strength or hardness of a material depends on the size of the sample, and the temperature and pressure. If you measure the hardness of a sample with only 60 carbon atoms, you may get very different results than if you measure the hardness of a 1 carat sample (containing 10^22 carbon atoms). For instance, a collection of molecules (each of which has 60 carbon atoms) may be a liquid. Whereas diamond is solid at Standard Temperature and Pressure.

By the way, what is the melting point of buckminsterfullerene?

Unfortunately i am unable to find an Internet based source for this, but i have heard this from many sources, although they may be inaccurate. If anyone can help...

The sources provided in the article presents a modified form of a fullerene, ultrahard fullerite, it may not be naturally occuring. What it does link to is an academic paper, which provides infromation that shows that the engineered substance can under these circumstances, scatch diamond. Though it is physically harder than diamond, Ultrahard fullerite is not made in meaningful enough quantities or avaible in these quantitis in order to be considered a naturally occuring material, if even a mineral. When larger quantities are avaible, we can learn if the microscopic hardness translates to a macroscopic hardness harder than diamond, something meaninful given the current industrial usages of diamonds. --02:19, 21 Jan 2005 (UTC)

Diamond is the hardest mineral substance known to man so you might be wondering why we have a page about chipped diamonds... Well, the key word here is mineral. Contrary to popular opinion, diamond is not the hardest substance in the world. In fact, you can scratch the surface of a diamond with a pop-top from a soda can. Now that we've blown your mind, we might as well finish it off... You can crack a diamond in half trying to scratch glass with it! It's true, if the diamond is at the wrong angle, or if you apply too much pressure, the diamond will cleave in half, maybe worse! Won't little Johnny be surprised when that science experiment fails... "Can Diamonds Be Chipped?" Are these diamond dealers correct in their claims? Can you scratch a diamond using sharpened aluminium or steel? 61.229.142.233 08:10, 12 Jun 2005 (UTC)

I guess Osmium doesn't count as a mineral? "Awesome Osmium" 61.229.142.233 08:10, 12 Jun 2005 (UTC)

I've already responded to most of this at Talk:Diamond#Can't be scratched?, but I'll point out again that the authors of that alarmist page have confused hardness with toughness. If you had read this article, you'd see that diamond's fragility is no secret. The pop-top claim is false; as for osmium (a metallic element, not a mineral), it comes in at only a 7 on Mohs' hardness scale. Your "Awesome Osmium" link again commits a serious lapse in understanding. It is confusing hardness with compressibility. In this respect, osmium is less compressible ("stiffer") than diamond, but certainly not harder. Here's the background information from bnl.gov (PDF file). -- Hadal 03:27, 13 Jun 2005 (UTC)

Thanks for the information and the PDF. [NiceIce, Osmium questions were mine] 61.229.125.147 16:13, 26 Jun 2005 (UTC)

Judging from the article Aggregated diamond nanorods, I think wikipedia is using bulk modulus as the measure of hardness? Even if not, I think a mention of Osmium in various pages including this one is worth it: Osmium has higher modulus than the diamond after all.1wonjae 16:57, 9 August 2007 (UTC)

Optical properties

What is the transmissivity of diamond (for specified wavelength(s)) through diamonds of specified type, specified color grade(s), and negligible flourescence? An answer that could be converted to units of [percentage of light transmitted through a straight diamond path 1 centimeter long] would be very nice. This would help answer the questions of how Diamond Color affects brilliance and optimum cut. -- Jasper 18:31, 19 November 2005 (UTC)

Electrical Properties of Diamond

When the article says that you can dope with Boron to obtain a p-type semiconductor but n-type hasn't been fabricated (or found) wouldn't Nitrogen-doped diamonds (yellow) be n-type semiconductors?

Making sufficiently conducting n-type diamond is an open problem. If you dope with nitrogen (or rely on the often naturally incorporated nitrogen), the donor activation energy is very high, at about 1.7 eV (c.f. 0.4 eV to activate boron acceptor dopants), i.e. very few free electrons are created at room temperature. If you move down the periodic table to phosphorus, the activation energy is much lower, at 0.6 eV. Note, though, that it took about 10 years to successfully get active P into diamond. Moving down the table once more, arsenic should have an activation energy of about 0.3 eV, according to theoretical calculations (disclaimer: my theoretical calculations; see my thesis). However, it will be extremely difficult to get the large arsenic atoms into diamond's tight lattice in such a way that they are actually electrically active; most of the time, they will complex with lattice vacancies and be essentially useless. --Steve Sque (I'm mentioned in the references of the main article) --Sque (talk) 17:04, 15 April 2008 (UTC)

I'm trying to get comments and suggestions here, http://en.wikipedia.org/wiki/User:Nerdseeksblonde/Marchywka_Effect

Didn't know this page existed but it is the only one that references Butler AFAIK :) Also, IIRC, the "n-type" dopant was putatitvely due to damage- mobilities or activation energy or something didn't make sense for low lying donor ( again IIRC circa 1995).

BTW, do you want a section on the electronic properties under mineral properties? As you no doubt know, people have used natural diamond for devices but these are generally optical and as anyone from Cree will tell you SiC is a better option esp for oxidation resistance etc. Nerdseeksblonde (talk) 11:25, 7 June 2009 (UTC)

Please provide a source on n-type diamond claim

I don't deny that it is possible that n-type mobile carriers have been created in something that has a 5.5ev gap, I just can't find evidence of it. If you can just provide one source that would be fine but since you made the claim you need to document it or just let it go. I have found sulfur, various groups, and maybe oxygen from Prins but nothing new on P doping. I haven't looked in a while, if you at least have a species of site ( intestitial would be interesting of course) that would help. IIRC, to get n-type material , you really had damage and either hopping transport ( not free carriers) or Eg was very low- more than just a little band tailing.

So, if you have carriers that move without a barrier and have mobilities even over a few hundred with a low T dependence that would be great. OTherwise, at least qualify the claim.

Also, if you want to put an electronics section here, there are a lot of diamond devices that elucidate the materials properties. The UV detectors are quite helpful and the cathodes possible helpful. The MIS devices I mention are at least as relevant as another paper on bipolar juncations (and without more documentations, this could be a Shottkey to graphite not a bipolar to n-0type diamond LOL).

Nerdseeksblonde (talk) 01:05, 26 June 2009 (UTC)

A quick answer is that search for "diamond phosphorus" on Web of Science returns 400 entries and on "Google books" returns 2000 entries. Thus before contensting world-wide diamond knowledge (phosphorus doping has been the most important diamond topic in the period 2001-2007 and is even closed down as solved) please discuss at talk pages first. I added a book on this topic into the article, but you can use my knowledge as well. When you substitute carbon atom in diamond, which has valence 4 by a group-V material (phosphorus, nitrogen), you produce an extra electron. In case of nitrogen, you need 1.7 eV to remove electron, which is too much for room-temperature heat. In case of phosphorus, the energy is 0.6 eV, and thus sufficient fraction of Ps is thermally ionized at 300 K making diamond a semiconductor. I anticipate a comment that P is "too large" for diamond. The answer is yes, but clever growth solves this not only for phosphorus, but even for larger nickel. CVD is especially efficient because diamond is grown in an "atom-by-atom" manner. The mobilities for phosphorus-doped diamond reach several hundreds (depend on doping level).

A side note: on the contrary, sulfur has not been confirmed as n-type dopant (see papers by R. Kalish), despite a few Phys. Rev reports. Experiments of Prins on ion implantation were not confirmed either, and ion implantation is not the way of diamond electronics as it graphitizes diamond.

Regarding "diamond electronics". You will find hundreds of papers claiming diamond devices. The vast majority are only claims, never brought to any practical stage (for obvious reasons, diamond is not friendly material for existing electronic manufacture). Diamond electronics is non-existent commercially. The strongest attempts are made by Element6, in the areas of high-power rectifiers and schottky diodes. A realistic application is diamond detectors for high-energy physics (but those a single devices made in the labs - too few facilities need them). Hope that helps. I am happy to explain more on the talk pages. You fell in in a wrong time of GA review of this article, thus I will reject hard any attempts to destabilize the paper by unconstructive criticism. Diamond electronics applications have nothing to do with this article on material properties, and there is no doubt whatsoever on reliability of phosphorus doping. Regards. Materialscientist (talk) 01:41, 26 June 2009 (UTC)

The reason there are so many entries is that the data is confusing and often the term is used glibly and optimistically but in the presence of doubt about what it really means- these are not all papers about diamond products that have been commercial successes. Certainly high mobilities or even hall mobilities with the right sign and a material that still seems to have the right indirect gap and carriers that don't have to hop- these are all encouraging. The way you have state the claim however may or may not be right. I guess if you want a one sentence overview citing the PN paper with UV emission may be suggestive but AFAIK they also saw a lot visible light- I'm sure there are good rationalizations for this but often supportive data is given preference. I would probably just confine the statement to the author who claims to have found this approach - that seems to be Koizumi- but if you mention it at all cite a historical perspective or two on failures that looked like successes. The citation you did add does seem to be from that group. The one citation I gave is for diamond MIS with something close to ODLTS is probably just as much a materials paper as is the PN diode you mention.Nerdseeksblonde (talk) 02:18, 26 June 2009 (UTC)

This is an interesting problem, and again for wiki all I thought was missing was an explicit reference given the historical issues. If you want to say it is reprodicibly doped in some useful way, that should be documented. I didn't yank it due to plausibility but it could stand some qualification and documentation. Any highly damaged diamond has been called n-type for quite a while...

In fall of 2006, that author is still talking like this, [1] "current status of n-type diamond research are mentioned mainly focused on the growth of high mobility n-type diamond and its electrical properties."

Another group in 2006 see high compensation, either they aren't doing it right or this isn't exactly a textbook process yet, [2] you really have to think about impurity bands and other things that create mobile looking electrons before claiming you have n-type diamond ( whatever that means). For wiki's purposes, you can probably verify your claims with a few citations, which is all I was asking, but the historical context of failed attempts probably deserves a phrase and citation too if you want to even discuss this.

LOL, according to this abstract, haven't read the paper, these guys confirm "doping" with SIMS, [3] "Phosphorus doping is confirmed by secondary-ion mass spectroscopy." If you just want to claim the lattice is "doped" or impure, that doesn't say anything about the electrical properties... Nerdseeksblonde (talk) 02:45, 26 June 2009 (UTC)

Sir, I offered you my knowledge as a dedicated specialist in this field. In return, you laugh at people you don't know and criticize papers you haven't bothered to read. I could provide you with a dozen of web-accessible books on this topic (and explain them for you), but you haven't even looked through the first one I gave. Good bye. Materialscientist (talk) 03:26, 26 June 2009 (UTC)

Earlier, you quoted the number of papers on n-type doping as having some weight.

I'm pointing out that many of these document controvery and confusion, not support for your one-line summary. You have presumably cited the most supportive works and indeed the citation you added was to a Koizumi book. The number of publications establishes notability of the issue- you have mentioned by your own assessment there have been many publications on diamond electronics that never quite worked out, I would suggest "n-type doping" literature is in the same state. Your claims of expertise don't mean anything in this anonymuous forum but as an expert you should appreciate how interesting this is, maybe even relevant to the superconductivity issue, and be happy to site a few primary sources at least in the talk page for consideration of "inclusion"[LOL] on main page. People have been making claims about n-type material, often involving P, for a while and many have turned out not to be reproducible. If you find this issue important enough to mention, I would just suggest changing the wording to be fair to the reader. There is no question that your text is verifiable as you claim- many reliable sources state now and have stated in the past that n-type doping has been achieved. If you are talking about reproducible, useful n-type material, you may do more justice with something to the effect of " While many attempts to get n-type material in the past were later shown to be flukes[1-2 examples or reviews], Koizumi et al demonstrated for the first time that production of active donors could populate the diamond conduction band [primary source] without ( say something about hopping, impurity bands, surface conduction, graphite, etc). The claim to n-type doping, while not exactly the discovery or superconductivity or a magnetic monopole, is probably worth explicit citation to a primary source. If it is the PN-diode paper just make it more clear.

Nerdseeksblonde (talk) 08:19, 26 June 2009 (UTC)

Did you read Koizumi's description of the state of affairs in the source you cite, LOL, See page 238 here,

http://books.google.com/books?id=pRFUZdHb688C&pg=RA1-PA237&source=gbs_toc_r&cad=4

[ I can't easily cut/paste this ] where he cites essentially all his own work and a successful VUV diamond detector as I mentioned before as being as illustrative as the PN diode, not high-energy MeV/ particle detectors. He seems to think these work using his doping approach. He also points to controversial results with B-D complexes. I can't see who he cites for 9-16 related to applications but apparently they have mobilities as high as 660 which is respectable. Again, it seems like his work is somewhat unique and I would just state it more along the lines of your statements about superconductivity or even name him specifically.

As per my original suggestion, a citation of this type is helpful in close proximity to your specific claim about the existence of a reproducible n-type doping process and the optical properties, emission and absoprtion, are useful in their own right and diagnostic of the electronic properties.

Nerdseeksblonde (talk) 08:50, 26 June 2009 (UTC)

How brittle and how tough is diamond?

Graph comparing stress–strain curves for brittle and ductile materials

I heard that the harder a material the more brittle it is. According to that diamonds must be among, if not the most brittle material in the world. Is that true? --92.74.26.115 (talk) 05:09, 11 January 2010 (UTC)

Brittle is not the opposite of hard. Glass is hard and brittle. Steel is hard and not brittle. That being said, diamonds worn as jewelry are more fragile than most people think. The ones with very low clarity grades tend to break; the better ones just get chipped. Zyxwv99 (talk) 20:51, 6 May 2013 (UTC)

User:92.74.26.115, we're using a very specific definition of brittle here. Crackers are brittle but soft (they don't bend much before they snap, but you can scratch them with your teeth). Jello will deform elastically quite a lot before it breaks, but the deformation isn't permanent: it bounces back. Cake dough will deform a lot before it breaks, and doesn't bounce back. The jello is therefore brittle, and the cake dough is not brittle but ductile. If you can't permanently bend the material, if it goes ~straight from bouncing to breaking, it is brittle. See the image on the right.

See fracture toughness for a measurement of toughness, which I think is what you mean. The article says that the toughness of diamond is 2 MPa·m^1/2, which is pretty fragile. The Diamond#Hardness article gives 7.5–10 MPa·m^1/2, moderate. This source says, in theory, 8.85. The number has been in this article for years. I've tagged it as needing a citation.

The hardness/toughness confusion is ancient; Pliny the elder wrote that you can test a diamond by putting it on an anvil and hitting it with a hammer. He wrote, wrongly, that real diamonds would not shatter. As User:Zyxwv99 said, diamonds actually shatter (and chip and crack) fairly easily. "Hard" means difficult-to-scratch, not difficult-to-shatter. If you want difficult-to-shatter, go for almost any metal alloy (some steels are very tough). HLHJ (talk) 03:28, 14 August 2017 (UTC)

References

Boiling point

Does diamond have a boiling point?

List of elements by boiling point lists it, on the other hand, this temperature is not mentioned in this article. --4096 tavua (talk) 14:12, 31 January 2010 (UTC)

Yes, but only at high (tens GPa) pressures. See phase diagram in carbon. Materialscientist (talk) 01:39, 1 February 2010 (UTC)

Doesn't boiling point of diamond require that there is liquid diamond? Doesn't diamonds chrystal break already when it melts? Or are we actually talking about sublimation point? --4096 tavua (talk) 08:05, 8 February 2010 (UTC)

At ambient pressure it sublimates, at high pressures it melts into a liquid and then boils. Materialscientist (talk) 08:14, 8 February 2010 (UTC)

I'm starting to feel an idiot, but I have to get this clear. What is the difference, if any, between liquid carbon, liquid graphite and liquid diamond? If there is no difference, should we stop talking about boiling point of diamond, but talk about boiling point of carbon? Thanks for patience! --4096 tavua (talk) 09:26, 8 February 2010 (UTC)

When they melt, they are same, but it takes different temperatures and pressures to melt graphite or diamond (or other forms of carbon) because of different arrangements between carbon atoms (different bond strengths). Materialscientist (talk) 09:32, 8 February 2010 (UTC)

So, there is no boiling point for diamond as such, am I right? The boiling point only applies to liquid carbon, not diamond, and it is a function of temperature and pressure. The melting point, however, depends of the starting solid phase as well. I went into this because there is much quoted web page that states not only that diamond can be boiled but also at what temperature it boils. This looks, pardon my French, insane to me. --4096 tavua (talk) 09:56, 8 February 2010 (UTC)

Correct, in all aspects (including the French one :) Word diamond is traditionally exploited to attract attention - who cares about boiling graphite. Materialscientist (talk) 10:01, 8 February 2010 (UTC)

Lattice Constant

Just a thought - but would it be worth having a section talking about the lattice constant of diamond - either in the Hardness and crystal structure section or only in the materials box. I found a web ref for this - but not sure how good it is - probably I have a book at work with it in it somewhere.

http://www.siliconfareast.com/lattice_constants.htm

Lattice Constant at 300 K (Å) Carbon (Diamond) - 3.56683 —Preceding unsigned comment added by Wideofthemark (talk • contribs) 13:46, 28 February 2010 (UTC)

Added into the infobox. Materialscientist (talk) 23:42, 28 February 2010 (UTC)

Thermal capacity?

I haven't found it in the article.--Grondilu (talk) 08:25, 29 November 2012 (UTC)

Teleological language

Do natural diamonds have defects and imperfections? Of course synthetic ones would, since an imperfection would be anything short of what the creators intended, on whatever scale they use to measure defects. To attribute the same characteristics to a product of nature would imply that mother nature (or some other divine creator) had a goal in mind when creating diamonds, and that we know what that goal was. According to the late Stephen Jay Gould's book Leonardo's Mountain of Clams and the Diet of Worms that idea started to go out the window a few centuries before Galileo was born, when some philosopher (I forget his name) came up with the idea of measuring things from the beginning instead of from the end. In ancient Greek though experiments, you dropped a stone from a certain height and evaluated its course based on where it ended up. When Galileo rolled a ball down an incline plane, he measured from the beginning, not the end. Diamonds were once said to have "flaws." Today gemologists speak of "inclusions" and "blemishes" precisely to avoid value-laden teleological language. (Except for the top clarity grade, where they just couldn't resist retaining the traditional word "flawless.") Zyxwv99 (talk) 20:59, 6 May 2013 (UTC)

I don't quite get the point of your argument, altho I'm aware in some of the more "left-field" areas of study, talking nonsense is an end in itself. In fact the speaking is it's own end, with any possibility of another being able to listen and actually understand it, being secondary to the sense of importance felt by the speaker, and the appropriate inclusion of buzzwords and neologism. The possible potential of such "listener" actually resolving anything of interest or value from such "communication" is a very dim and distantly considered intention, if at all. Post-modernism, the only intellectual field entirely dedicated to the study of itself.

However, if you want an actual answer related to actual diamonds and their imperfections... Consider a "perfect" diamond to be a single crystal of carbon arranged in the usual correct way. Carbon linked to carbon linked to carbon, from one edge to the other. Any deviation from this, within the boundaries of the diamond, would be an "imperfection". Not in a moral sense, or as a failure to make real an intention. But an imperfection in the existential process of being a diamond. The parts of a diamond, that are not made of diamond, yet lie within the spatial boundaries of a particular diamond, may thus be just as well called "imperfections" in a simply technical manner, while making no teleological presumptions or value-judgments.

So, while disdained by jewellers, we can know, in as far as it is possible to "know" or "not know" anything at all, that Mother Nature loves all her minerals, and in her eyes there are no imperfections, only the little things that make a small piece of allotropic carbon unique and special to her. 188.29.164.99 (talk) 20:30, 4 September 2013 (UTC)

Just wanted to mention that "teleology" is neither a buzzword nor a neologism. It's been in the dictionary for centuries, and was a core concept in philosophy of science during the Age of Enlightenment (also known as the 18th century). Since most people would consider this an advanced vocabulary word, I provided an explanation of what it means. "Value-laden" is also a concept they teach in college: it means putting your own opinions into something when it isn't called for, for example by using loaded words or phrases.

On the other hand, I'm willing to withdraw my complaint about the use of the term "imperfection." I was thinking gemologists, not jewelers, but it's still the same issue: this article is about diamond the mineral, and thus properly falls under the domains of mineralogy and crystallography. Every field of human endeavor has it's own specialized vocabulary or "terms of art." From a linguistic standpoint these terms are "correct" to the extent that they are defined and understood within that field. Zyxwv99 (talk) 04:05, 3 January 2014 (UTC)

Diamond transistors

Since these could have interesting properties (eg operation at high temperature, high voltage etc) I'd like to see this expanded eg under electrical properties (despite it being many years from any practical/commercial use) since it reveals interesting electrical properties of (doped) diamond (electron mobility, breakdown voltages, electron effective mass ...) all as a function of temperature. - Rod57 (talk) 05:52, 4 January 2016 (UTC)

Seeing materialscientists comments above on n-type diamond - is there a better article for this material to expand into ? - Rod57 (talk) 05:52, 4 January 2016 (UTC)

If you aim for devices, you can start Diamond electronics - there are hundreds of studies on all kinds of devices, and some (photodetectors) have long been commercial, though with limited use. DeBeers (Element 6) advocated that diamond will replace SiC in high-power switches, which are used in common electrical power stations.

If you aim for mobility, effective mass and similar parameters, better expand this article - diamond differs from conventional semiconductors in that its intrinsic properties are much more reliable when extracted from (doped or undoped) crystals than devices; device properties depend too much on preparation. Materialscientist (talk) 06:08, 4 January 2016 (UTC)

OK, maybe call it Diamond as a semiconductor with a section on devices ? - Rod57 (talk) 06:16, 4 January 2016 (UTC)

Diamond electronics is a standard term in the field, which is used in book and conference titles. Diamond as a semiconductor is too long and vague; it is somewhat equivalent to doped diamond, which is a valid topic, but it is much wider than electronics - doped diamonds have been studied much more than devices made from them. Materialscientist (talk) 06:24, 4 January 2016 (UTC)