Grain Growth in Al-2% Cu Thin Films

Abstract

DISCLAIMERThis document was prepared as an account of work sponsored by the United States Government. Neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any ir_ormation, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, _ademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California. The views and opi_ons of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or The Regents of the University of California and shall not be used for advertising or produc: endorsement purposes. J 'Lawrence Berkeley Laboratory is an equal opportunity employer. LBL--31203 DE92 002263Grain Growth in AI-2% Cu Thin Films ABSTRACTThe grain size and grain growth kinetics in sputter deposited AI-2% Cu films on silicon substrates were determined by TEM for various film thicknesses and anneal times, temperatures and methods. Grain sizes were found to be typically lognomaally distributed. The as-deposited grain size (do) dependence on film thickness (TIl) was found to be do = C TH1/2, due to competitive grain growth during film formation. Annealed grain size (d) after Rapid Thermal Annealing (RTA) for time (t) at temperature (T) is described by the general equation d -do = C TH 0.7 {t exp (-AEa/kT) }1/8,where ZkEa= 0.85 ev for 0.4 I.tm films and AEa = 1.1 ev for 0.8 I.tm films. Grain growth is largely saturated for these anneals. Grain growth is shown to be more extensive during RTA anneals than furnace annealing and more extensive in 0.4 l.tm films than 0.8 I.tm films for equivalent RTA cycles. The results are discussed in terms of models, simulations and previous results of grain growth in thin metal films.

In Search of Cool Flow Accretion onto Galaxies: Where Does the Disk Gas End?

“…Another recent revelation is that the declining metallicity gradient of both stars and gas appears to flatten out beyond several disk scalelengths (q.v. Vlajic 2010; Sanchez et al 2014). It is interesting to consider whether some of the extended H I envelopes identified in nearby groups (e.g., Leo, Cen, M81, M83) normally attributed to tidal debris from high column regions is in fact compressed material from proto-disk regions.…”

Hot Extrusion of Nanostructured Al-Powder Alloys: Grain Growth Control and the Effect of Process Parameters on Their Microstructure and Mechanical Properties

“…[1,22,23] At the same time, copper segregates at the grain boundaries and dislocations. [24] The phase sequence and microstructure of Al(Cu) have been studied extensively.…”

“…Grain growth in Al(Cu) begins around 200°C [1,22,23] and progresses with increasing temperature. [1,22,23] At the same time, copper segregates at the grain boundaries and dislocations.…”

On the radial abundance gradients in discs of irregular galaxies

“…The radial distribution of gas-phase oxygen abundances traced by H ii regions has been investigated in the disks of many spiral galaxies (Vila-Costas & Edmunds 1992;Zaritsky et al 1994;van Zee et al 1998;Pilyugin et al 2004;Moustakas et al 2010;Gusev et al 2012;Pilyugin et al 2014a;Sánchez et al 2014). It was found that almost all spiral galaxies show radial abundance gradients in the sense that their inner H ii regions (i.e., those closer to the galactic centers) have higher oxygen abundances than the outer ones.…”