J. Kushauer et al., ATHERMAL MAGNETIZATION AVALANCHES AND DOMAIN STATES IN THE SITE-DILUTED METAMAGNET FEXMG1-XCL2, Physical review. B, Condensed matter, 53(17), 1996, pp. 11647-11655
Magnetization avalanches occurring at the field-induced metamagnetic f
irst-order phase transition in dilute layered antiferromagnets are exp
erimentally studied on FexMg1-xCl2, x=0.8 and 0.9, at low temperatures
and simulated at T=0. Discrete magnetization steps are related to ava
lanches starting with single spin flips at distinct lattice sites. Dip
olar interactions lower the threshold fields and smoothen the magnetiz
ation curves. Their hysteresis is anomalously large within our model c
alculation neglecting infinite range dipolar interactions and infinite
temperatures. The ''critical disorder''-induced crossover of the phas
e transition from first to second order is estimated to occur at x app
roximate to 0.6.