TY - JOUR
T1 - Molecular-dynamics study of the decomposition of an unstable Ni-Ag alloy
AU - Colla, Thomas J.
AU - Urbassek, Herbert M.
AU - Averback, Robert S.
N1 - Funding Information:
TJC is grateful for support by the Deutsche Forschungsgemeinschaft. We acknowledge discussions with Kai Nordlund.
PY - 1999/6
Y1 - 1999/6
N2 - In an attempt to understand how ballistically mixed alloys decompose under the influence of an ion-induced thermal spike, we perform model molecular-dynamics simulations in unstable random NixAg1-x alloys. We study the time dependence of decomposition as a function of the temperature, density and concentration in the alloy by monitoring the short-range order parameter and atom mobility. Mobility is diffusion-like; its temperature dependence is determined by activation energies of 2.6 (3.6) eV for Ag (Ni) atoms. The decomposition is strongly assisted by the reduced atom densities which are characteristic of thermal spikes. Decomposition works most efficiently in a mid-concentration range (x = 0.5), since here the heat of mixing liberated by the decomposition process heats the system and enhances diffusion.
AB - In an attempt to understand how ballistically mixed alloys decompose under the influence of an ion-induced thermal spike, we perform model molecular-dynamics simulations in unstable random NixAg1-x alloys. We study the time dependence of decomposition as a function of the temperature, density and concentration in the alloy by monitoring the short-range order parameter and atom mobility. Mobility is diffusion-like; its temperature dependence is determined by activation energies of 2.6 (3.6) eV for Ag (Ni) atoms. The decomposition is strongly assisted by the reduced atom densities which are characteristic of thermal spikes. Decomposition works most efficiently in a mid-concentration range (x = 0.5), since here the heat of mixing liberated by the decomposition process heats the system and enhances diffusion.
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U2 - 10.1016/S0168-583X(98)01026-X
DO - 10.1016/S0168-583X(98)01026-X
M3 - Conference article
AN - SCOPUS:0033516062
SN - 0168-583X
VL - 153
SP - 369
EP - 377
JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
IS - 1-4
T2 - Proceedings of the 1998 4th International Conference on Computer Simulation of Radiation Effects in Solids (COSIRES)
Y2 - 15 September 1998 through 19 September 1998
ER -