Crossover from classical to random-field critical exponents in As-doped TbVO4 | |
Article | |
关键词: ISING-MODEL; PHASE-TRANSITIONS; CRITICAL-BEHAVIOR; FE0.93ZN0.07F2; BIREFRINGENCE; SCATTERING; | |
DOI : 10.1103/PhysRevB.61.11197 | |
来源: SCIE |
【 摘 要 】
Using birefringence techniques we have measured the critical exponents beta, gamma, and delta in As-doped TbVO4, a structural realization of the random-field Ising model where random strain fields are introduced by V-As size mismatch. For pure TbVO4 we observe the expected classical critical exponents, while for a mixed sample with 15% As concentration our results are beta = 0.31 +/- 0.03, gamma = 1.22 +/- 0.07, and delta = 4.2 +/- 0.7. These values are consistent with the critical exponents for the short-range pure Ising model in three dimensions in agreement with a prediction by Toh. The susceptibility data showed a crossover with temperature from classical to random-field critical behavior.
【 授权许可】
Free