TY - JOUR

T1 - Nonequilibrium fluctuations, effective temperature, and effective interactions driven by irradiation of alloys

AU - Enrique, Raúl A.

AU - Bellon, Pascal

N1 - Funding Information:
Stimulating discussions with Georges Martin and Robert S. Averback are gratefully acknowledged. This material is based upon work partly supported by the U.S. Department of Energy, Division of Materials Sciences under Award No. DEFG02-91ER45439, through the Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign, and by the University of Michigan.

PY - 2004/12

Y1 - 2004/12

N2 - We study alloy systems subjected to sustained particle irradiation, where short-ranged thermally assisted diffusion competes with the finite-ranged random atomic exchanges forced by irradiation. For the case of binary alloys undergoing phase separation, we introduce a kinetic continuum description of the evolution of the composition field under irradiation, with a self-consistent treatment of the composition fluctuations. We derive an analytical formula for the structure factor at steady state. In the limiting case of short-ranged ballistic jumps, this formula indicates that the effective temperature criterion originally derived by G. Martin [Phys. Rev. B 30, 1424 (1984)] applies not only to the driving force but to the fluctuations as well. In the case of finite-ranged ballistic jumps, however, the formula indicates that the concept of an effective temperature breaks down, but that one can make use of a more general approach involving effective atomic interactions. In particular, under appropriate irradiation conditions, finite-ranged ballistic jumps lead to finite-ranged effective interactions, which translate into the dynamical stabilization of finite-scale composition patterns.

AB - We study alloy systems subjected to sustained particle irradiation, where short-ranged thermally assisted diffusion competes with the finite-ranged random atomic exchanges forced by irradiation. For the case of binary alloys undergoing phase separation, we introduce a kinetic continuum description of the evolution of the composition field under irradiation, with a self-consistent treatment of the composition fluctuations. We derive an analytical formula for the structure factor at steady state. In the limiting case of short-ranged ballistic jumps, this formula indicates that the effective temperature criterion originally derived by G. Martin [Phys. Rev. B 30, 1424 (1984)] applies not only to the driving force but to the fluctuations as well. In the case of finite-ranged ballistic jumps, however, the formula indicates that the concept of an effective temperature breaks down, but that one can make use of a more general approach involving effective atomic interactions. In particular, under appropriate irradiation conditions, finite-ranged ballistic jumps lead to finite-ranged effective interactions, which translate into the dynamical stabilization of finite-scale composition patterns.

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U2 - 10.1103/PhysRevB.70.224106

DO - 10.1103/PhysRevB.70.224106

M3 - Article

AN - SCOPUS:13844264498

VL - 70

SP - 224106-1-224106-6

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 0163-1829

IS - 22

M1 - 224106

ER -