
	Where results make sense

Topic: Kirkendall effect

Related Topics

Diffusion

Crystal structure

Elephant

In the News (Wed 9 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Kirkendall effect - Wikipedia, the free encyclopedia
		The Kirkendall effect is the migration of markers that occurs when markers are placed at the interface between an alloy and a metal, and the whole is heated to a temperature where diffusion is possible; the markers will move towards the alloy region.
		His paper demonstrated the importance of the Kirkendall effect in wire bonding technology, but also showed the significant contribution of any impurities present to the rate at which precipitation occurred at the wire bonds.
		Both Kirkendall voids and Horsting voids are known causes of wire bond fractures, though historically this cause is often confused with the purple colored appearance of one of the five different aluminium-gold intermetallics, commonly referred to as "purple plague" and less often "white plague".
	en.wikipedia.org /wiki/Kirkendall_effect (331 words)

	The Discovery and Acceptance of the Kirkendall Effect
		The Kirkendall Effect is important in connection with bonding between different materials and, in particular, raises the practical concern of controlling and suppressing the voids that are produced in the boundary region at a bonding interface.
		Ernest Kirkendall was born in Michigan in 1914.
		To illustrate the importance of his discovery, the Kirkendall Effect Symposium on Interdiffusion and Phenomena that Depend on Net Vacancy Flows was held during the TMS Fall Meeting in October 1991.
	www.tms.org /pubs/journals/JOM/9706/Nakajima-9706.html (3610 words)

	Scientific phenomena named after people - Wikipedia, the free encyclopedia
		Baskerville effect – the fictional Charles Baskerville of the novel The Hound of the Baskervilles
		Lense-Thirring effect – Josef Lense and Hans Thirring
		Sunyaev-Zeldovic effect – Rashid Sunyaev and Yakov Zeldovic
	en.wikipedia.org /wiki/Scientific_phenomena_named_after_people (357 words)

	Current Research Activities (Site not responding. Last check: 2007-10-20)
		Brown, D.D., Rodgers, J., and Steurer, R.A. The effect of external nasal dilators on submaximal exercise responses.
		Therefore, the purpose of this study was to examine the effects of the dilator on metabolic and respiratory responses during exercise.
		This study investigated the effects of external nasal dilators on metabolic and respiratory responses during submaximal exercise.
	www.cast.ilstu.edu /dbrown/current.htm (2405 words)

	MSD Research Highlight
		For example, when two metals, zinc and copper, are place in contact and heated, an alloy (brass in this case) forms at the boundary and expands in the direction of the faster-moving species, zinc.
		Kirkendall discovered that the atoms of the two solids do not change places directly; rather atoms diffuse into voids in the wake of the faster-moving material.
		To exploit this effect on the nanoscale, the Alivisatos groups coat cobalt nanocrystals with sulfur.
	www.lbl.gov /~msd/PIs/Alivisatos/04/04-10_hollowxtal.html (539 words)

	[No title]
		The elucidation of the Kirkendall effect manifestations is of fundamental importance because it contributes greatly to the understanding of the interactions between the constituents of the solder system.
		2- The manifestation of the effects accompanying reactive phase formation in solids such as the Kirkendall effect and development of porosity are influenced by the generation and relaxation of the diffusion-induced stress.
		A phenomenological approach based on the concept of the Kirkendall velocity construction was introduced to rationalise the behaviour of the inert markers inside a reaction zone.
	www.univie.ac.at /cost531/projects/GP3.doc (6796 words)

	Prof. King-Ning Tu, UCLA
		The effect of current crowding on joule heating as well as on stress concentration will be analyzed.
		Huang, E. Yeh, Z. Zhang, and K. Tu, "The effect of contact resistance on current crowding and electromigration in ULSI multi-level interconnects," Materials Chemistry and Physics, 77, 377-383 (2003).
		Alam, Y. Chan, K. Tu, and J. Kivilahti, “Effect of 0.5 wt% Cu in Sn-3.5% Ag solder ball on the solid state interfacial reaction with the Au/Ni/Cu bond pad for ball grid array (BGA) applications,” Chemistry of Materials, Vol.
	www.seas.ucla.edu /ms/faculty1/tu.html (2233 words)

	Publications of Kai Nordlund (Site not responding. Last check: 2007-10-20)
		The effect of collision cascades on pre-existing point defects in crystalline materials was studied by simulating 5 keV collision cascades in gold, copper, aluminum, platinum and silicon.
		In contrast to the annealing effects of pre-existing damage in the FCC metals, in silicon the amount of new damage created by a cascade is roughly independent of the number of initial point defects.
		Effects of the local atomic neighbourhood on the chemisorption were examined in order to compare the results with experiments.
	beam.helsinki.fi /~knordlun/pub (9873 words)

	[No title] (Site not responding. Last check: 2007-10-20)
		Special attention is paid to the effect of the diffusion mechanism on the kinetic path of the configuration: interesting results are found in the early stages of unmixing as well as of phase separation coupled to ordering, in the BCC structure.
		An effect of pair interaction potentials, activation barriers for the migration of A- or B-atoms and of the vacancy concentration was studied.
		In lightly n-doped superlattices, an additional consideration of the electrical effect due to bandgap inhomogeneities and/or hetero-junctions has allowed quantitative fits of experimental results and thus refute recent doubts on the validity of the Fermi-level effect model itself and on whether the triply-negatively-charged group III vacancy is indeed the dominating defect.
	www.mrs.org /meetings/spring98/absbook/AbstractBookZ.html (16685 words)

	Jonas Frantz homepage (Site not responding. Last check: 2007-10-20)
		The effect is explained as a strain-induced effect analogous to the classical Kirkendall effect.
		We study the mechanism of this effect using classical molecular dynamics augmented with models describing the breaking of covalent bonds induced by electronic excitations.
		The re-alignment effect of the Co nanoclusters found in experiments was found to be due to a collective rotational movement of the whole cluster during the burrowing process.
	koti.welho.com /jfrantz/public.html (1135 words)

	Science Beat: Hollow Nanocrystals and How to Mass Produce Them
		This was the clue to Ernest Kirkendall's discovery that the atoms of the two solids don't change places directly; rather diffusion occurs where voids open, making room for atoms to move in.
		On the nanoscale, the Kirkendall effect explains why a fast-diffusing cobalt nanocrystal leaves a hollow center behind as it moves into a surrounding sulfide-compound shell.
		The nanospheres were remarkably uniform: depending on the proportions of the starting materials, their hollow centers were 40 to 70 percent as big as the initial crystal, but hole size varied no more than 13 percent in any given batch.
	www.lbl.gov /Science-Articles/Archive/sb/May-2004/02-MSD-hollow-nanocrystals.html (955 words)

	Kirkendall Borgers/barstow/douglas/kirkendall Family Tree Page. My Family History, Including Borgers, Barsto (Site not responding. Last check: 2007-10-20)
		Kirkendall Pottery offers ceramics classes, studio space, and fine ceramics in the downtown Washington, D. America's brave men and women have earned your support.
		The Discovery and Acceptance of the Kirkendall Effect: The Result of a Short Research Career.
		Bicycling the Pacific Coast; Tom Kirkendall kirkendall circendall om tm to tomkirkendall irkendall krkendall kikendall kirendall kirkndall kirkedall kirkenall.
	www.99hosted.com /names11001.html (400 words)

	OhioLINK ETD: Wu, Kaisheng
		Model α+α' alloys were designed so that changes in the microstructure could be attributed to either capillarity or the Kirkendall effect.
		It has been found that the Kirkendall effect, which was introduced by setting atomic mobilities to different values, changed the diffusion path slope and led to the formation of "horns" on the two-phase diffusion path.
		Also the initial slope of the diffusion path differs significantly from the earlier work and the path is time dependent due to temporal changes in the microstructure.
	rave.ohiolink.edu /etdc/view?acc_num=osu1064257423 (389 words)

	Session B7.1 (Site not responding. Last check: 2007-10-20)*
		Up to recently, the effect of point defect fluxes (irradiation induced precipitation) was handled by models for the inverse Kirkendall effect, while the effect of ballistic mixing was treated with a Lyapunov function formalism (effective temperature).
		Taking advantage of an adiabatic relaxation of the fast variables (point defects supersaturation), the Lyapunov function formalism is extended and incorporates now the effect of the coupling between point defects and solute fluxes.
		Beyond describing the various effects of irradiation on phase stability in a single frame work, the theory predicts new features of microstructural evolution under irradiation.
	www.mrs.org /meetings/fall97/abstract_book/B/node47.html (140 words)

	van Dal biopic (Site not responding. Last check: 2007-10-20)
		Despite more than half a century of rather intensive work, a number of fundamental aspects associated with the manifestation of the Kirkendall effect is still not fully understood.
		It is clear that understanding the problem calls upon a study of the fundamental aspects of solid state diffusion processes as well as experimental techniques to investigate the net mass-flow accompanying interdiffusion in the solid state.
		One of the experimental techniques to study the Kirkendall effect is the multi-foil technique.
	www.chem.tue.nl /tvm/svmbiopics/dalbio.htm (424 words)

	Robert Franklin Mehl, March 30, 1898—January 29, 1976 \| By C. S. Smith and W. W. Mullins \| Biographical Memoirs (Site not responding. Last check: 2007-10-20)
		The effect of the great depression in 1929 and his own interests, however, combined to make him leave in 1932 after only one year.
		Two famous examples are the campaigns he waged against the concept of dislocations and against the role of vacancies in diffusion, especially as manifested by the Kirkendall effect (movement of inert markers in a diffusion couple providing evidence for a vacancy mechanism of diffusion).
		Many years later, when Mehl was confined to bed, he apologized to Kirkendall, who made a personal visit, and whom he told he wished he had an important effect named after him.
	www.nap.edu /html/biomems/rmehl.html (3638 words)

	Leslie & Co: In the News - GQ Eye, Winter 1999
		In this, a bar of 70-30 brass (70% copper-30%zinc) was wound with fine molybdenum wire (molybdenum is insoluble in copper and brass) and then plated with about 0.1 in.
		The Kirkendall effect suggests that this may be a moot point.
		Thanks are also due to John Emmett of Crystal Chemistry for information on the Kirkendall Effect, Richard Pollak of United Radiant Applications for information on his product, and Martin Guptill for slicing and polishing several pieces of the products of each manufacturer in the name of science.
	www.leslieandco.com /GQEye_winter99.htm (1968 words)

	Holey nanocrystals could aid core research (April 2004) - News - nanotechweb.org
		We followed up on it and realized that it is a very general effect, based on the well known formation of voids by the ‘Kirkendall Effect’.”
		The Kirkendall Effect, discovered by Ernest Kirkendall in 1947, provided the first evidence that atomic diffusion occurs by a process of vacancy exchange, rather than by direct swapping of atoms.
		According to Alivisatos, the oxidation and sulphidation of cobalt under vapour is mainly controlled by the outward diffusion of cobalt cations.
	nanotechweb.org /articles/news/3/4/17/1 (461 words)

	The Kirkendall Effect
		The Kirkendall experiment proves the existence of vacancy diffusion in the vast majority of metallic materials.
		The Kirkendall Effect in Solid-State Diffusion (Ph.D. Thesis)
		The large concentrations of vacancies on the nickel sublattice in off-stoichiometric NiAl_(1+x) where x is less than or equal to 1, occur because there is an increase in the number of aluminium atoms able to bond with nickel, due to the excess of aluminium [9].
	www.msm.cam.ac.uk /phase-trans/kirkendall.html (1467 words)

	Thesis Abstract (Site not responding. Last check: 2007-10-20)
		The effect of heating time on the extent of removal of silver has been studied.
		The silver concentration profile across the thickness of the impure gold specimen heated for 5 hr, 10 hr, and 15 hr heating time show that there is a continuous decrease of silver from the center to the surface.
		This was brought about by the Kirkendall effect.
	www.iitk.ac.in /mme/mtTheses/2002/Y010628.html (250 words)

	Cumulative effects
		Where Nicholas is headed with these observations is a discussion of cumulative effects, a theory that's a relatively young area of scientific study.
		This is when you simply sum up the effects of all the individual human activities in a watershed.
		This is when the effect of one activity interacts with the effect of another activity, or several activities, in a way that makes the impact more than just the sum.
	eesc.orst.edu /salmon/human/cumulative.html (920 words)

	SUMMARY - "REACTION DIFFUSION and SOLID STATE CHEMICAL KINETICS"
		These effects were taken into account in equations describing the rate of growth of the layer under conditions of its simultaneous dissolution in the liquid phase or evaporation into the gas phase.
		The difference in diffusivities of the components in a growing chemical compound layer is often connected, especially in the literature on physics and metallurgy and especially in relation to intermetallics, with the Kirkendall effect.
		Comparison of the consequences following from the physicochemical and purely diffusional approaches is given to show that the latter is one of the limiting cases of the former.
	users.i.com.ua /~dybkov/V/BOOK2/summary.htm (828 words)

	ScienceWeek (Site not responding. Last check: 2007-10-20)
		The effect was first observed in the alloying of copper and zinc to form, in this case, brass.
		Before Kirkendall's publication more than 50 years ago, it was believed that the metal diffusion resulted from a concerted interchange of metal atoms, when in fact it takes place via an exchange of vacancies.
		This analogy originates from the early work on quantum confinement effects in semiconductor nanocrystals, where the electronic wavefunctions are predicted(4) to exhibit atomic-like symmetries.
	scienceweek.com /2004/sb040611-3.htm (1106 words)

	Metal-Physics: Research (Site not responding. Last check: 2007-10-20)
		Over recent years, the activities of our group have been devoted to phenomena that occur in metallic multicomponent diffusion couples, whenever there is an imbalance of the components' diffusion fluxes: Local volume contractions and expansions, the formation of pores, and the specimens' dimensional changes perpendicular to diffusion direction.
		All of these phenomena are closely related to - or are part of - the Kirkendall effect.
		All of the above techniques could also be applied to any effects of morphological surface changes and structural changes if they are in the micrometer range.
	www.physik.uni-oldenburg.de /Docs/met/research.html (176 words)

	Nat' Academies Press, Biographical Memoirs V.78 (2000)
		In the case of vacancy diffusion, he was persuaded by friends of Kirkendall not to reject for publication the now classic work by Kirkendall and Smigelskas,8 which he had held up for half a year as chief reviewer, but rather to allow publication and to submit discussion to the paper setting forth his objections.
		The history of this controversy is discussed in an article by Hideo Nakajima 9 and a subsequent response by da Silva.10 A positive benefit of Mehl's passionate stance on these issues was the focused motivation he generated for himself and colleagues to resolve the disputes by incisive research.
		Episode on the discovery of the Kirkendall effect.
	www.nap.edu /books/030907035X/html/128.html (3926 words)

	ScienceWeek
		In 1947, Smigelkas and Kirkendall reported the movement of the interface between a diffusion couple, i.e., copper and zinc in brass, as the result of the different diffusion rates of these two species at an elevated temperature.
		This phenomenon, now called the "Kirkendall effect", was the first experimental proof that atomic diffusion occurs through vacancy exchange and not by the direct interchange of atoms.
		Starting with cobalt nanocrystals, the authors demonstrate that their reaction in solution with oxygen and either sulfur or selenium leads to the formation of hollow nanocrystals of the resulting oxide and chalcogenides.
	scienceweek.com /2004/sb040625-3.htm (1278 words)

	ME481/581 F98 Final Exam (Site not responding. Last check: 2007-10-20)
		a) The Kirkendall Effect was discovered from an experiment by Kirkendall and Smiegelskas in which it was found that the atomic species in a diffusion couple in general diffuse at different rates.
		The consequense of the different diffusivities is that a net flux of vacancies will occur in the direction of the faster diffusing component.
		If this vacancy concentration becomes too large, the vacancies coalesce into pores or voids, which are known as Kirkendall porosity, or Kirkendall voids.
	oregonstate.edu /instruct/me481/Exams/F98/ME481F98Final.html (1447 words)

Try your search on: Qwika (all wikis)