학술논문
Structural, magnetocaloric effect, critical behavior, and spin resonance analysis of monovalent-doped manganites Nd0.6 Sr0.4−x Mx MnO3 (x = 0.0, 0.1; M = K, Na)
Document Type
Original Paper
Source
Journal of Materials Research. 38(20):4559-4572
Subject
Language
English
ISSN
0884-2914
2044-5326
2044-5326
Abstract
In-depth research of the effects of monovalent doping on magnetocaloric properties of manganites Nd0.6Sr0.4−xMxMnO3 (x = 0.0, 0.1; M = K, Na) synthesized by sol–gel were studied. The magnetization-versus-temperature curves reveal a second-order phase transition from ferromagnetic to paramagnetic at the Curie temperature. The Curie temperature is found to decrease from 276 K in the Nd0.6 Sr0.4 MnO3 to 250 K and 248 K in Nd0.6 Sr0.3 K0.1 MnO3 and Nd0.6 Sr0.3 Na0.1 MnO3 , respectively. The Nd0.6 Sr0.3 K0.1 MnO3 has the highest isothermal magnetic entropy change (5.45 J/kg.K), whereas Nd0.6 Sr0.3 Na0.1 MnO3 has the highest relative cooling power (144.41 J/Kg), which denotes its potentiality in cooling fields. The charge difference of Sr, K, and Na influence the ratio of Mn4+ /Mn3+ , causing significant fluctuations in Nd0.6 Sr0.4 MnO3 manganite.Various approaches are used to derive the critical exponents, and they are shown to be consistent with the values predicted by the tricritical mean field. This work highlights that monovalent ions doped are promising for magnetic refrigeration near room temperature.Graphical abstract: