Talk:Hafnium/Archive 1

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Archive 1

Energies

The phrase "The nuclear isomer Hf-178-m2 is also a source of energetic, 2.45 MeV gamma rays." is utterly wrong as this nucleus can never emit a gamma with energy more than 0.5 MeV with non-negligible probability. (source: http://ie.lbl.gov/toi/nuclide.asp?iZA=720778 ). Actual gamma energy is 12.7 and 309 KeV for transition from that long-living level with exitation energy of 2446.05 KeV and halflife of 31 years (because transition is done to nearby levels with exitation energies 2433.326 and 2136.513 KeV), and is in range from 89 to 574 KeV for transitions from other levels. —The preceding unsigned comment was added by 85.21.179.36 (talk • contribs) .

Tagged as dubious in the article. You seem to know what you're talking about, be BOLD and fix it! Femto 11:50, 16 November 2006 (UTC)

Thanks for the contribution as it illuminated a shortcoming of the existing text. However, from the reference link you cite above, under the section titled "Most Recent ENSDF Data (12/2002)" if you take the link available from the button marked "Level scheme" you will see that the two gamma transitions that you correctly say start from the isomer finish on energy levels that then emit more gammas in a sequential cascade. Elsewhere it is reported that each decay of an isomer on the average results in thesequential emission of 8 gamma photons (more or less) but the energies total to about 2.446 MeV. The use of about is because some of the less energetic members of the cascade are sometimes internally converted and some small part of the 2.45 MeV of the isomer ends up in electron energies. However, most of the stored energy ends up in sequences of gammas whose summed energies is almost up to 2.45 MeV. I have edited the entry to try to make this point that you have raised completely clear.

--Drac2000 22:00, 16 November 2006 (UTC)

Excessive deletion

The deletion of a paragraph because of a concern for one sentence is excessive and so has been reverted. The Wiki policy WP:CON requires discussion on this page before established consensus is deleted. The particular paragraph involved has been the subject of the immediately preceding section of discussion and represented a consensus.

--Drac2000 23:33, 16 December 2006 (UTC)

Your invocation of CON makes me hope that we don't have a WP:OWN issue on our hands. I Don't see any particular discussion or consensus relating to the subject of the material that I removed and there is certainly no policy requiring that consensus be reached for every common edit. There are several sentances in the article which state, as if they are completely unquestioned, that things like gamma ray lasers can be made with Hf. The Hf isomer induced gamma emission controversy is really over. No one important in the field even takes the possibility seriously and the article should reflect what is now basically a closed consensus on the subject. --Deglr6328 01:34, 17 December 2006 (UTC)

Beetstra is moving us toward consensus. I am supplying 2 of the needed citations. Hopefully someone will do the other 2 cn flags.

--Drac2000 13:37, 17 December 2006 (UTC)

That is indeed what I try. May I suggest that you try to combine the two paragraphs into one separate section, and to try and add some peer-reviewed references to that? Thanks. --Dirk Beetstra ^{T C} 14:58, 17 December 2006 (UTC)

Thanks, Dirk. I guess our messages crossed in the ether. I was hunting the Peer reviewed refs as you were adding this message. I had to go over to another site to get them and so just inserted them. Didn't see your thoughtful recommendation until after the changes were made. Maybe it's in good shape now. Also, I found that the stray link at the bottom was actually the reference (now serving as Ref. 1.) for the first cn. The remaining cn is verified by the same ref as is now, Ref. 1, but I do not know how to use a same reference number a second time. If you can do that please consider replacing the last cn with another usage of Ref.1.

--Drac2000 15:18, 17 December 2006 (UTC)

Thanks! I have added ref 1 for the remaining {{cn}} (what you do, you give the first ref a name with the parameter name: "<ref name="name1">contents</ref>", If you reuse the ref, you can then add them with a "<ref name="name1" />". see meta:cite.php for more info). Could you check my work? I still believe the two sections about the cascade should be combined into a special section, I might give that a try later. --Dirk Beetstra ^{T C} 16:05, 17 December 2006 (UTC)

Thanks to you! I have learned an important element of editing.

--Drac2000 16:33, 17 December 2006 (UTC)

Unique nuclear aspects

Here I try to discuss Dirk Beetstra's perceptive recommendation that a separate section be added to contain the peculiar aspects the isomer of Hf-178 offers at the nuclear level. Reference to the "history" tab for this article shows about 75 edits since May, 2006, but the discussion page shows little discussion for such extensive editing. There was extensive and highly "spirited" discussion, but it ended up archived over at the discussion for Induced gamma emission. Unhappily for the worthy element Hafnium, it has a nucleus designed to excite terrific (and justifiable) concern. At first this was described in a section of this page, but the concern was so great and the issue so complex that material spilled over into Nuclear isomer, Induced gamma emission and Induced_gamma_emission:_Hafnium_controversy. The thinking finally emerged that Hafnium was an element needing somewhat parallel treatment with other rather unremarkable elements, but the nucleus and its excitation of one of its isotopes (mass 178) gave the element a notability that needed to be remarked, but the explication could be made in adequate detail only in a separate page at Induced gamma emission(IGE). However, there again, IGE had a non-controversial history and level of interest. It just had the misfortune to act as an umbrella over the controversy over its application to the peculiar isomer of one isotope of Hafnium. A re-examination of the whole situation would be welcome, but very time-consuming; perhaps converging back to the present point. I recommend a read of the archived discussion over at Induced gamma emission.

--Drac2000 16:33, 17 December 2006 (UTC)

Copies by the New York Times

http://www.nytimes.com/2007/01/27/technology/27chip.html

this article copies verbatim a portion of the start of the Wikipedia article. —The preceding unsigned comment was added by 83.41.195.84 (talk) 11:56, 27 January 2007 (UTC).

Fair use rationale for Image:Sigilum Facultatis Naturalis.JPG

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BetacommandBot (talk) 11:30, 21 January 2008 (UTC)

Abundance and market price

In view of the new economic significance of hafnium it would be good to see something on its abundance and accessibility in the Earth's crust and its market price. Lumos3 15:47, 30 January 2007 (UTC)

Agree on the crust info, but market prices are worth little because they fluctuate and vary according to purity and quantity and so on. We've been trying to avoid such info, or even the attempt to include it. The CRC in the past hasn't been so wise, but it's a new world, and one that changes rapidly. Too rapidly even for Wikipedia in this matter. Price for each purity and form and bulk for each vendor for each element would require its own wiki. If you want to start one for any element, and then tend it, you go, girl! S B H arris 01:48, 31 January 2007 (UTC)

Just added a scholarly reference that supply was running out. Same chemist predicted the same for Indium#Occurrence and consumption. The editors there dismissed it as "scaremongering." Maybe the same disclaimer can be found here. I have no axe to grind. Just adding a supposedly reputable reference. Student7 (talk) 02:41, 5 May 2008 (UTC)

According to this article, hafnium is running out and we'll be out of it, as a planet, by 2017.

B-class review

A todo list to get this to B-class

Expand tags

I'm pretty sure those are not needed b/c none of the sources I have mention much more than what is already in this article. Sure, some expansion is needed to upgrade this, but I don't think that issue is bad enough to warrant expand tags.

Deleted the expand tags.--Stone (talk) 14:38, 22 September 2008 (UTC)

Lead section

Mention of history needed: Prediction, Moseley, named for Copenhagen, Discovery, (Costner & von Hevesy)

Added a sentence to the lead about the discovery.--Stone (talk) 14:38, 22 September 2008 (UTC)

Expand a bit on the other parts of the lead

Expanded the use a little bit.--Stone (talk) 14:38, 22 September 2008 (UTC)

2 decent-sized paras max

Try to fit it into 2.--Stone (talk) 14:38, 22 September 2008 (UTC)

Compounds section

Make s subsection of ==Characteristics== and remove the expand tag

Most other elements have their own compounds section!--Stone (talk) 14:38, 22 September 2008 (UTC)

History

Break-up long second para

Broke them up!--Stone (talk) 14:38, 22 September 2008 (UTC)

Mention that this was next to last element with stable isotopes discovered.

Now it mentions: was next to last element discovered.--Stone (talk) 14:38, 22 September 2008 (UTC)

Applications

Mention why there aren't many uses for this element (similarity to Zr, difficulty in separating...)

Added a paragraph to the Occurrence and production section. --Stone (talk) 14:38, 22 September 2008 (UTC)

De-listify ===Other uses===

This will be done tonight.--Stone (talk) 14:38, 22 September 2008 (UTC)

Done it!--Stone (talk) 18:09, 22 September 2008 (UTC)

Importance rating

I'm not sure why this is high-importance. There certainly isn't much to say about this element and there aren't many uses for it.

--mav (talk) 17:40, 21 September 2008 (UTC)

Importance: I thought that all the main-group elements are high-imp (a few of them are top though), while the lanthanoids and most of period 7 are mid. Nergaal (talk) 21:59, 21 September 2008 (UTC)

The only transition elements that are main group elements are the in group 12. But even if hafnium were in the main group, I wouldn't consider it high importance b/c: It does not head its group/period, is not biologically important, not widely-used b/c of how hard it is to extract, not common on earth or the universe, does not have many outstanding properties (except for neutron absorption of one of its isotopes), not historically very important (missed that boat by being the second to last stable element found, and not the last), in the second to last popularity category we have, and a few other things (not to mention, that there isn't much to say about the element). B/c of all that, I'd rate it as mid-importance (if it were not for the neutron absorbence and the fact that it was predicted by Bohr's model, I'd rate it as low). The more I think of it, the more I think we need a point system for importance that would assign points across a broad range of areas. I'd just like us to have a more systemic grading system for importance. --mav (talk) 23:05, 21 September 2008 (UTC)

moved discussion to the main talkpage of the project. Nergaal (talk) 00:10, 23 September 2008 (UTC)

historical inconsistency

in the current version of the "History" section, it claims that Hafnium was discovered and then predicted by the Bohr theory of the atom. by itself that doesn't make sense.

my understanding of it, from Richard Rhodes' book on the atomic bomb, is that Bohr elaborated his theory of electron shells, connected that up with the periodic table, and predicted hafnium would be found around zirconium ores, at which point de Hevesy et al started looking for it, and then found it just before Bohr's Nobel acceptance speech. --98.217.8.46 (talk) 14:19, 29 October 2008 (UTC)

Thanks! Wrong and Right! The validating the original 1869 prediction of Mendeleev. Soon thereafter, the new element was predicted to be associated with zirconium by using the Bohr theories.... The Soon thereafter means after Mendeleev prediction not after the discovery, but this has to be changed!--Stone (talk) 15:13, 29 October 2008 (UTC)

By early 1923 several physicists and chemists, for example Nils Bohr^[1] and Charles R. Bury^[2] suggested that element 72 should resemble zirconium and therefore is not part of the rare earth elements group. This suggestions where based on the the Bohr theories of the atom, the x-ray spectroscopy of Mosley and the chemical arguments of Friedrich Paneth ^[3]. Encouraged by these points and the reappearing claims of Urbain in 1922 ^[4] that element 72 is a rare earth element and already discovered by Urbain in 1911 motivated Coster and Hevesy searched for the new element in zirconium ores.

References

^ Bohr, Niels. The Theory of Spectra and Atomic Constitution: Three Essays. p. 114.
^ Bury, Charles R. (1921). "LANGMUIR'S THEORY OF THE ARRANGEMENT OF ELECTRONS IN ATOMS AND MOLECULES". Journal of the American Chemical Society. 43 (7): 1602–1609. doi:10.1021/ja01440a023.
^ Paneth, F. A. (1922). "Das periodische System". Ergebnisse der Exakten Naturwissenschaften 1. pp. 362–403.
^ Urbain, M. G. (1922). "Sur les séries L du lutécium et de l'ytterbium et sur l'identification d'un celtium avec l'élément de nombre atomique 72". Comptes rendus. 174: 1347–1349. Retrieved 2008-10-30.

Intel/IBM Breakthrough

Intel and IBM unveil new chip technology Breakthrough, using new material, will allow processors to become smaller and more powerful. Anyone want to explain/expand/incorporate into the article? This is out of my league. /Blaxthos 15:57, 27 January 2007 (UTC)

Found another article. [1] Jumping cheese ^Cont@ct 03:23, 28 January 2007 (UTC)

I think it's the same article; CNN republished the reuters report. /Blaxthos 03:48, 28 January 2007 (UTC)

Heres two more, EE times article Times Online Article Peoplez1k 19:57, 30 January 2007 (UTC)

I'm no expert (or even educated on the subject) and am hesitant to try and incorporate into the article -- do we have any experts who would lend a hand? Thanks! /Blaxthos 21:13, 30 January 2007 (UTC)

I removed the implication that Intel and IBM are partners; rather I think that they are competitors. At least, IBM's press release mentions AMD, not Intel. [2] If anyone can clarify further, please do. GeoGreg 22:20, 31 January 2007 (UTC)

IBM and Intel did their respective research separately but completed around the same time since the 45nm node size was where it was becoming attractive to replace replace the gate oxide as quantum tunneling had been an increasingly bigger problem as the number of atoms that make up gate oxide have been shrinking to increase gate capacitance. AMD (not Intel) did partnered with IBM in their research. Intel has uses hafnium-based dielectric for their 45nm chips for over a year now in its Penryn and Nehalem processors. AMD recently started with Phenom II and Shanghai Opteron processors. The main benefit of replacing the silicon dioxide gate dielectric that has been used for decades is it allows an increase in gate capacitance (ability to hold an electrical charge) without leakage effects (wastes power by creating heat. heat can damage the chip or require a more complex/costly cooling solutions). 209.30.228.224 (talk) 03:32, 27 January 2009 (UTC)

Dragon's Breath

Why does this article have a photo of Dragon's Breath being performed? The connection that hafnium is somewhat pyrophoric, and that some other pyrophoric material is used for this is a bit of a stretch. Since hafnium itself isn't used in this context, the photo seems gratuitous and out of place.FellGleaming (talk) —Preceding undated comment added 15:39, 31 March 2010 (UTC).

Talk

Thanks to all who are recently contributing to making this page even better. --Drac2000 13:17, 20 September 2006 (UTC)

The "Production" section mentions "fractionatal crystallization". Shouldn't it read "fractional crystallization"? --Lontche (talk) —Preceding undated comment added 11:40, 12 January 2011 (UTC).

Yes, fixed. Thanks. Materialscientist (talk) 12:09, 12 January 2011 (UTC)

File:Hf-crystal bar.jpg to appear as POTD soon

Hello! This is a note to let the editors of this article know that File:Hf-crystal bar.jpg will be appearing as picture of the day on November 2, 2012. You can view and edit the POTD blurb at Template:POTD/2012-11-02. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page so Wikipedia doesn't look bad. :) Thanks! —howcheng {chat} 18:39, 1 November 2012 (UTC)

Picture of the day

A sample of a 1.7 kg (3.7 lb) hafnium crystal bar, made by the van Arkel-de Boer process. Hafnium is a lustrous, silvery gray, tetravalent transition metal that chemically resembles zirconium and is found in zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869. Industrially, it is used in filaments and electrodes.Photo: Alchemist-hp

Archive – More featured pictures...

File:Hafnium pellets with a thin oxide layer.jpg to appear as POTD soon

Hello! This is a note to let the editors of this article know that File:Hafnium pellets with a thin oxide layer.jpg will be appearing as picture of the day on December 30, 2015. You can view and edit the POTD blurb at Template:POTD/2015-12-30. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. — Chris Woodrich (talk) 23:35, 10 December 2015 (UTC)

Picture of the day

Pellets of 99.9% pure argon-arc remelted hafnium, with visible crystalline structures. The colors are a thin-film effect in the oxide layer; this chemical element is generally a lustrous, silvery gray, tetravalent transition metal. Hafnium is widely used in filaments and electrodes, as well as in some superalloys.Photograph: Heinrich Pniok

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File:Hafnium ebeam remelted.jpg to appear as POTD soon

Hello! This is a note to let the editors of this article know that File:Hafnium ebeam remelted.jpg will be appearing as picture of the day on September 3, 2017. You can view and edit the POTD blurb at Template:POTD/2017-09-03. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. — Chris Woodrich (talk) 12:15, 22 August 2017 (UTC)

Picture of the day

Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, making it the last stable element to be discovered. Hafnium is named for Copenhagen, where it was discovered.Photograph: Heinrich Pniok

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Occurrence: error

It is not true, that Hf doesn't occur as free element in the nature.

http://www.mindat.org/min-47058.html

Eudialytos (talk) 16:29, 20 November 2016 (UTC)

That's on the Moon, though. Hf and Zr cannot effectively be separated on Earth due to the lack of impacts allowing their fractionation (anyway they would be oxidised). But I will change it. Double sharp (talk) 01:55, 21 November 2016 (UTC)

Thanks. Yes, the Moon regolith has zones with a reductive "assemblage", though there are portions were oxidative-conditions compounds were found (KReO4).Eudialytos (talk) 20:13, 29 August 2017 (UTC)

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[1] Bohr, Niels. The Theory of Spectra and Atomic Constitution: Three Essays. p. 114.

[2] Bury, Charles R. (1921). "LANGMUIR'S THEORY OF THE ARRANGEMENT OF ELECTRONS IN ATOMS AND MOLECULES". Journal of the American Chemical Society. 43 (7): 1602–1609. doi:10.1021/ja01440a023.

[3] Paneth, F. A. (1922). "Das periodische System". Ergebnisse der Exakten Naturwissenschaften 1. pp. 362–403.

[4] Urbain, M. G. (1922). "Sur les séries L du lutécium et de l'ytterbium et sur l'identification d'un celtium avec l'élément de nombre atomique 72". Comptes rendus. 174: 1347–1349. Retrieved 2008-10-30.

[1]

[2]

[3]

[4]