Crossover from classical to random-field critical exponents in As-doped TbVO4
Abstract
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 behaviour.
Keywords
Cite
@article{arxiv.cond-mat/0002158,
title = {Crossover from classical to random-field critical exponents in As-doped TbVO4},
author = {C. H. Choo and H. P. Schriemer and D. R. Taylor},
journal= {arXiv preprint arXiv:cond-mat/0002158},
year = {2009}
}
Comments
7 pages including 4 figures; To be published in Physical Review B