Impact of sintering temperature on room temperature magneto-resistive and magneto-caloric properties of Pr2/3Sr1/3MnO3

TL;DR

This study investigates how sintering temperature affects the magneto-resistive and magneto-caloric properties of Pr2/3Sr1/3MnO3, revealing optimal conditions for potential room-temperature magnetic refrigeration applications.

Contribution

It provides new insights into the relationship between sintering temperature and magnetic properties of Pr2/3Sr1/3MnO3, identifying optimal processing conditions for enhanced magneto-resistive and magneto-caloric effects.

Findings

Maximum magneto-resistance of 58% at 5T and 32% at 1T.

Maximum magnetic entropy change of 7.8 Jkg-1K-1 at 5T.

Optimal properties achieved at sintering temperature of 1400°C.

Abstract

Magneto-resistive and magneto-caloric properties of polycrystalline Pr2/3Sr1/3MnO3 have been studied as a function of sintering temperature (Ts) between 1260-1450{\deg}C. Reitveld refinement of their X-ray diffraction (XRD) patterns confirms their single phase crystalline structure with orthorhombic Pbnm space group. The point of maximum value of temperature coefficient of resistance (TCRmax) and Curie temperature (Tc) decreased slightly with Ts. Magneto-resistance (MR) and magnetic entropy ({\Delta}SM) increased markedly with sintering temperature. This could be attributed to the observed sharpness of both the magnetic and resistive transitions due to better grain connectivity. Optimum results are obtained for the sample with Ts = 1400{\deg}C. MR at Tc of the same is found to be as large as 32% at 1T and 58% at 5T magnetic fields. The maximum entropy change ({\Delta}SMmax) near its Tc is 2.3Jkg-1K-1 and 7.8 Jkg-1K-1 upon 1T and 5T fields change respectively. These characteristics [MR (32% 1T, 58% 5T) and reasonable change in magnetic entropy (7.8Jkg-1K-1, 5T)] generate possibility that the optimized compound can be used as a potential magnetic refrigerant close to room temperature.