Room temperature magnetic entropy change and magnetoresistance in La_{0.70}(Ca_{0.30-x}Sr_x)MnO_3:Ag 10% (x = 0.0-0.10)

TL;DR

This study investigates the magnetic and magnetocaloric properties of La-based manganite with Sr and Ag doping, revealing significant magnetoresistance and entropy change near room temperature, suitable for magnetic refrigeration applications.

Contribution

It reports the effects of Sr and Ag doping on magnetic and magnetocaloric properties of La0.70(Ca0.30-xSrx)MnO3, highlighting potential for room temperature magnetic refrigerants.

Findings

Maximum magnetoresistance of 49% at 3 Tesla.

Magnetic entropy change of 7.6 J/Kg·K at 5 Tesla near 300 K.

Curie temperature remains near 298 K with doping.

Abstract

The magnetic and magnetocaloric properties of polycrystalline La0.70(Ca0.30-xSrx)MnO3:Ag 10% manganite have been investigated. All the compositions are crystallized in single phase orthorhombic Pbnm space group. Both, the Insulator-Metal transition temperature (TIM) and Curie temperature (Tc) are observed at 298 K for x = 0.10 composition. Though both TIM and Tc are nearly unchanged with Ag addition, the MR is slightly improved. The MR at 300 K is found to be as large as 31% with magnetic field change of 1Tesla, whereas it reaches up to 49% at magnetic field of 3Tesla for La0.70Ca0.20Sr0.10MnO3:Ag0.10 sample. The maximum entropy change (\DeltaSMmax) is 7.6 J.Kg-1.K-1 upon the magnetic field change of 5Tesla, near its Tc (300.5 K). The La0.70Ca0.20Sr0.10MnO3:Ag0.10 sample having good MR (31%1Tesla, 49%3Tesla) and reasonable change in magnetic entropy (7.6 J.Kg-1.K-1, 5 Tesla) at 300 K can be a potential magnetic refrigerant material at ambient temperatures.