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Abrupt field-induced transition triggered by magnetocaloric effect in phase-separated manganites

L. Ghivelder·R. S. Freitas·M. G. das Virgens·M. A. Continentino·H. Martinho·L. Granja·M. Quintero·G. Leyva·P. Levy·F. Parisi
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Abstract

The occurrence at low temperatures of an ultrasharp field-induced transition in phase separated manganites is analyzed. Experimental results show that magnetization and specific heat step-like transitions below 5 K are correlated with an abrupt change of the sample temperature, which happens at a certain critical field. This temperature rise, a magnetocaloric effect, is interpreted as produced by the released energy at the transition point, and is the key to understand the existence of the abrupt field-induced transition. A qualitative analysis of the results suggests the existence of a critical growing rate of the ferromagnetic phase, beyond which an avalanche effect is triggered.

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L. Ghivelder, R. S. Freitas, M. G. das Virgens, M. A. Continentino, H. Martinho, L. Granja, M. Quintero, G. Leyva, P. Levy, F. Parisi. 2004-04-15. Abrupt field-induced transition triggered by magnetocaloric effect in phase-separated manganites. https://doi.org/10.1103/physrevb.69.214414

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