Critical behavior and magnetocaloric effect in La0.7Ba0.25Nd0.05Mn1-xCuxO3

T V Manh,Y Pham,K P Shinde,D Nanto,H Lin,S C Yu,D R Munazat,D S Razaq,K C Chung,D H Kim,Budhy Kurniawan

doi:10.1063/1.5079842

Abstract

In this work, the magnetic and magnetocaloric properties of La0.7Ba0.25Nd0.05Mn1-xCuxO3 samples (x = 0 - 0.07) synthesized by the sol-gel method are presented. The compounds exhibited a second-order phase transition (SOPT) of ferromagnetic-paramagnetic (FM-PM) phase transition following Banerjee’s criterion. Curie temperature TC decreased with increasing doping concentration. The critical behavior analysis using modified Arrott plots (MAP) showed a short-range FM ordering. Significant entropy change of samples was observed near the TC, which decreased with Cu content. The SOPT nature of compounds was confirmed by both the universal curves and scaling hypothesis.

Highlights

INTRODUCTIONThe ABO3 type perovskite is one of the most promising materials for the spintronic devices and magnetic refrigeration with many electrical and magnetic properties. The perovskite manganites (LaMnO3 compounds) are believed to be a good candidate for magnetic refrigeration technology, which is working on basic principal magnetocaloric effect (MCE). This effect is associated with change of temperature and entropy of magnetic material under the application of magnetic field, while MCE becomes maximal near a magnetic phase transition
This effect is associated with change of temperature and entropy of magnetic material under the application of magnetic field, while magnetocaloric effect (MCE) becomes maximal near a magnetic phase transition
It has been reported that the influence of the ferromagnetic double exchange (DE) interaction and Jahn– Teller (JT) distortions could lead to strongly coupled spin, lattice, and electronic degrees of freedom such as in lanthanum manganites, which are responsible for the reported novel properties around phase transitions

Summary

INTRODUCTION

The ABO3 type perovskite is one of the most promising materials for the spintronic devices and magnetic refrigeration with many electrical and magnetic properties. The perovskite manganites (LaMnO3 compounds) are believed to be a good candidate for magnetic refrigeration technology, which is working on basic principal magnetocaloric effect (MCE). This effect is associated with change of temperature and entropy of magnetic material under the application of magnetic field, while MCE becomes maximal near a magnetic phase transition. The perovskite manganites (LaMnO3 compounds) are believed to be a good candidate for magnetic refrigeration technology, which is working on basic principal magnetocaloric effect (MCE).. The perovskite manganites (LaMnO3 compounds) are believed to be a good candidate for magnetic refrigeration technology, which is working on basic principal magnetocaloric effect (MCE).6,7 This effect is associated with change of temperature and entropy of magnetic material under the application of magnetic field, while MCE becomes maximal near a magnetic phase transition. The LaMnO3 compounds consist of two types of magnetic interactions, FM interaction associated with the double-exchange (DE) pair of Mn3+–Mn4+, and anti-FM interactions linked to the super-exchange (SE) pairs of Mn3+–Mn3+ and Mn4+–Mn4+ Their interaction strength depends on the ratio of Mn3+/Mn4+, and the structural parameters, which are accountable for various behaviours of phase transitions and MCE.. Eq (1), used to fit the isothermal magnetization curves and the magnetic entropy change, is represented by the Landau coefficients as SM (T , H)

EXPERIMENTAL

RESULTS AND DISCUSSION

CONCLUSIONS