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Magnetic Transitions and Ferromagnetic Clusters in RuSr2(Eu,Ce)2Cu2O10+d

Y. Y. Xue·B. Lorenz·D. H. Cao·C. W. Chu
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Abstract

The macroscopic magnetizations of a RuSr2(Eu0.7Ce0.3)2Cu2O10+d sample were investigated. A ferromagnet-like transition occurs around T_M in the low-field magnetization. Highly nonlinear M(H), non-Curie-Weiss susceptibility, and slow spin-dynamics, however, were observed up to T_1 approx 2-3 T_M. In addition, an antiferromagnet-like differential-susceptibility maximum of Ru appears around a separate temperature T_AM between T_1 and T_M. The data are therefore consistent with a phase-separation model: superparamagnetic clusters (or short-range spin-orders) are first precipitated from the paramagnetic matrix below T_1, followed by an antiferromagnetic transition of the matrix at T_AM and an apparent ferromagnetic (FM) transition around T_M, where the long-range spin-order is established in the FM species imbedded in the matrix.

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Y. Y. Xue, B. Lorenz, D. H. Cao, C. W. Chu. 2002-11-16. Magnetic Transitions and Ferromagnetic Clusters in RuSr2(Eu,Ce)2Cu2O10+d. https://doi.org/10.1103/physrevb.67.184507

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