Avalanche-like metamagnetic transition in (LaNd)CaMnO manganites

JOURNAL OF ALLOYS AND COMPOUNDS

卷:680

Article

Ghivelder, L.¹  Eslava, G. G.¹  Freitas, R. S.²  Leyva, G.^3,4  Parisi, F.^3,4 

[1] Univ Fed Rio de Janeiro, Inst Fis, BR-21941972 Rio De Janeiro, RJ, Brazil

[2] Univ Sao Paulo, Inst Fis, BR-05314970 Sao Paulo, SP, Brazil

[3] Comis Nacl Energia Atom, Dept Fis, Ctr Atom Constituyentes, Bahia Blanca, Buenos Aires, Argentina

[4] Univ Nacl Gen San Martin, Escuela Ciencia & Tecnol, Buenos Aires, DF, Argentina

关键词: Manganite;    Metamagnetic;    Phase separation;    Magnetic avalanche;   

DOI  :  10.1016/j.jallcom.2016.04.152

来源: Elsevier

【 摘 要 】

We investigate the nature of ultrasharp metamagnetic transitions in La5/8-yNdyCa3/8MnO3 manganites. These compounds change from a low temperature ferromagnetic metallic state at low Nd doping to a charge-ordered antiferromagnetic insulator for high Nd content. At an intermediate doping a phaseseparated state is established. At low temperatures (similar to 2 K), an avalanche-like field-induced metamagnetic transition is observed, where the entire compound changes abruptly from one phase to the other. The behavior of this ultrasharp transition is investigated using magnetization and specific heat measurements. We found a first order transition in the specific heat associated with discontinuous jumps in the magnetization. A strong increase of the sample temperature is simultaneously observed. The results are interpreted in terms of latent heat released from the field-induced enhancement of the ferromagnetic fraction, triggering the avalanche process. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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