Magnetocaloric effect in (La1-xSmx)0.67Pb0.33MnO3 (0 ? x ? 0.3) manganites near room temperature

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Tarih

2015

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Elsevier Science Sa

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

We present an investigation on structure, magnetic and magnetocaloric properties of the perovskite manganites (La1-xSmx)(0.67)Pb0.33MnO3 (x = 0, 0.1, 0.2, 0.3) synthesized by sol-gel technique. The XRD patterns show that all synthesized samples have reflections typical of the perovskite structure with orthorhombic symmetry. Thermomagnetic measurements showed that all the samples display a paramagnetic-ferromagnetic transition with decreasing temperature. The Curie temperature decreases with increasing Sm content from 358 K for x = 0-286 K for x = 0.3. We determined the isothermal magnetic entropy changes of all the samples from the magnetization measurements and furthermore measured the adiabatic temperature change of the sample for x = 0.3 directly. The results showed that the adiabatic temperature change, determined using together the entropy change and the specific heat and the value obtained by direct temperature change measurements both give 1.3 K for a magnetic field change of 3 T at about 280 K. We also measured the cyclic adiabatic temperature-change of the sample and the results indicate that the sample undergoes a reversible temperature-change on field-cycling which is essential for magnetic refrigeration. (C) 2015 Elsevier B.V. All rights reserved.

Açıklama

Anahtar Kelimeler

Manganites, Magnetocaloric effect, Curie temperature, Magnetic entropy, Adiabatic temperature change

Kaynak

Journal of Alloys and Compounds

WoS Q Değeri

Q1

Scopus Q Değeri

Q1

Cilt

650

Sayı

Künye