Do thermal spikes contribute to the ion-induced mixing of Ni into Zr, Ti, and Pd?

Abstract

Low-temperature ion beam mixing rates for Ni-Ti, Zr-Ni, and Pd-Ni bilayers significantly exceeded binary collision estimates, and appeared quite sensitive to thermodynamic driving forces. In the absence of a temperature dependence such a behavior is commonly ascribed to interdiffusion within thermal spikes. However, the Ni-Ti mixing rate was seen to vary linearly with nuclear damage energy for irradiation with 600 keV Xe, Kr, or Ar, 300 keV Ne or N, or 200 keV N ions, or 1 MeV Au ions (literature value). This excludes overlapping thermal spikes. An expression was derived for mixing due to nonoverlapping thermal spikes, but this could also not explain our results.

Ion beam induced surface and interface engineering

“…3. Mixing model (nonoverlapping) assuming local spherical spike formation at the ends of the individual recoil cascades by Børge-sen et al [438], radiation enhanced diffusion controlled by the defects left by the quenched displacement cascades and the temperature of the sample [439]. 4.…”

Interdiffusion processes at irradiated Cr/Si interfaces

“…The slowing down of impinging atoms with high kinetic energy (few hundreds of KeV) leads to the mixing of atoms at the atomic scale in alloys, semi conductors or insulators [9,10,11,12]. By changing the energy of the incident beam, it is possible to create buried interfaces at well defined depths.…”

Nanostructural characterization of CrN and CO thin films on silicon substrate, modified by ion bombardment

“…Model lokalnih "termičkih šiljaka" su razvili Børgesen i njegovi saradnici da bi objasnili linearnu zavisnost brzine atomskog miješanja od gustine deponovane energije, koja se javlja kod metalnih sistema srednjih vrijednosti atomskog broja [77,78] …”

“…Odgovarajuće debljine "implantirane zone" Konačno, korištenjem Drude-ovog modela, dovedena je u vezu kompleksna dielektrična funkcija, ε(ω) = ε 1 (ω) + i . ε 2 (ω), sa kompleksnom električnom provodljivošću sistema, Za opisivanje "netermalnog" rasta regiona miješanja, unutar kojeg nastaje čvrsti rastvor ili amorfna odnosno kristalna faza, razvijeno je više teorijskih modela [72,[77][78][79][80]83].…”

“…Ukoliko ova oblast predstavlja čvrsti rastvor može se primijeniti balistički model [72,73], koji uzima u obzir samo dvočestične sudare, ili modeli "termičkih šiljaka", koji uključuju hemijski aktiviranu difuziju atoma uslijed nastanka lokalnih [77,78] odnosno globalnih [79,80] "šiljaka". Sa druge strane, za oblasti miješanja unutar kojih dolazi do nastanka jedinjenja, primjenjuju se modeli koji opisuju proces miješanja kao rezultat difuzije atoma tokom formiranja jedinjenja pri balističkim uslovima [83] ili u prisustvu lokalnih [107] Fe/a-Si sistema je nađeno da amorfizovana struktura podloge obezbjeđuje skoro duplo veću brzinu miješanja u odnosu na Fe/c-Si sistem [109,110].…”