Structural, magnetic, magnetocaloric, investigations on La0.8−xKxSr0.2Mn0.95Ni0.05O3 (x = 0.05, 0.10 and 0.15) at room temperature

Abstract

This paper investigated the effect of A-site doping K+ on the structural, morphological, and magnetic properties of La0.8Sr0.2Mn0.95Ni0.05O3. La0.8-xKxSr0.2Mn0.95Ni0.05O3 (LKSMNO) were synthesized by the sol–gel (S–G) method. The XRD analysis and refinement have revealed that LKSMNO were the rhombohedral structure of the R-3c space group (No. 167) and the cell volume increased with increasing K+ doping. The ratio of Mn4+/Mn3+ becomes larger with the increase of K+ content. The magnetic studies indicate that the Curie temperature (TC) of LKSMNO increases from 305 K to 320 K with the increase of K+, and the second order magnetic phase transition occurs around the TC. When the external magnetic field (H) is 5 T, the maximum magnetic entropy changes (-ΔSMmax) were 4.00 J/(kg K), 4.11 J/(kg K), and 3.39 J/(kg K), respectively, near TC. The relative cooling power (RCP) of LKSMNO were 272.28 J/kg, 288.15 J/kg, and 304.90 J/kg.