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

L.GHIVELDER; ...; PABLO EDUARDO LEVY; ET AL.

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

Año: 2004 vol. 69 p. 214414 - 214418

0163-1829

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, A.G. Leyva, P. Levy and F. Parisi 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 steplike 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. PHYSICAL REVIEW B 69, 214414 (2004).