A brief discussion of the magnetocaloric effect in thin films of manganite doped with chromium

G. Campillo, A. I. Figueroa, O. Arnache, J. Osorio, J. M. Marin Ramirez, L. Fallarino

Resultado de la investigación: Contribución a una revistaArtículo de la conferencia

Resumen

In this work we report on the magnetocaloric effect of La2/3Ca1/3MnO3 (LCMO) and La2/3Ca1/3Mn0.94Cr0.06O3 (LCMCrO) manganite thin films grown by DC magnetron sputtering on LaAlO3 (100) substrates. X-ray diffraction shows that both doped and undoped films crystallize in the orthorhombic structure. Magnetic measurements show a decrease in both the Curie temperature, TC , and the saturation magnetization, MS , for the LCMCrO sample. The change in the magnetic entropy (ΔSm ) was extracted from hysteresis loops at different temperatures around the ferromagnetic to paramagnetic transition, displaying a maximum of entropy change (ΔSm ) max near TC in both films. Moreover, a shift in (ΔSm ) max toward temperatures above TC with increasing magnetic field and a broadening of the entropy change curve were observed. Results of refrigeration cooling power show a lower efficiency for LCMCrO. In order to obtain a local insight into the magnetic interactions of these films, measurements of X-ray absorption spectroscopy and X-ray magnetic circular dichroism (XMCD) were performed. XMCD suggests that an antiferromagnetic coupling between Mn4+ - Mn3+ is favored with Cr3+ incorporation, which reduces the Mn L 2,3 XMCD signal and results in a decrease of MS and (ΔSm ) max in LCMCrO films.

Idioma originalInglés
Número de artículo012013
PublicaciónJournal of Physics: Conference Series
Volumen1247
N.º1
DOI
EstadoPublicada - 17 jun 2019
Evento6th National Conference on Engineering Physics, CNIF 2018 and the 1st International Conference on Applied Physics Engineering and Innovation, APEI 2018 - Bucaramanga, Colombia
Duración: 22 oct 201826 oct 2018

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