Thermopower of Al1-xSix solid solutions in vicinity of lattice instability
Sluchanko, NE × Glushkov, VV Demishev, SV Kondrin, MV Samarin, NA Moshchalkov, Victor Brazhkin, VV #
AMER INST PHYSICS
Journal of experimental and theoretical physics vol:86 issue:1 pages:190-196
date:Russian Acad Sci, Inst Gen Phys, Moscow 117942, Russia; Russian Acad Sci, Inst High Pressure Phys, Troitsk 142092, Moscow Region, Russia
The thermopower coefficient as a function of temperature, S(T), has been measured in nonequilibrium superconductors, such as Al1-xSix substitutional solid solutions and Al-Si alloys on various decay stages. When aluminum is substituted with silicon, the contribution to the thermopower due to phonon-drag effects, which are dominant in pure aluminum at low temperatures, is suppressed, and low-temperature anomalies in S(T) detected in compositions near lattice instability limit are determined by the diffusion component of the thermopower. The low-temperature anomalies in the thermopower and the notable increase in the coefficient in front of the linear term in S(T) are attributed to effects of thermopower renormalization due to the electron-phonon interaction enhancement with "soft modes" in the face-centered cubic (FCC) lattice of Al1-xSix solid solutions. The nature of these anomalies in S(T) is analyzed in terms of the Kaiser and Reizer-Sergeev models. (C) 1998 American Institute of Physics.