MAGNETIZATION JUMPS IN THE HYSTERESIS CURVES OF THE DILUTED ANTIFERROMAGNETS A(2)FE(1-X)IN(X)CL(5)CENTER-DOT-H2O (A=K, RB)

Single crystals of dilute samples of the antiferromagnets A(2)Fe(1-x)I n(x)Cl(5) . H2O (A = K, Rb) exhibit a net remanent magnetization M(r) below the ordering temperature (T-N). This M(r) saturates in fields of few Oe. In this work we focus on the hysteresis loops M versus H obta ined at several temperatures below T-N. The loops were obtained after field cooling (FC) the samples in a field of similar to 1 Oe applied a long the easy axis. The loops were asymmetric and showed a series of w ell defined jumps in M versus H curves for T < T-N. This behavior sugg ests that a domain structure is present, and that the jumps are associ ated with abrupt changes in the domain structure.