Investigation of field-controlled magnetocaloric switching and magnetodielectric phenomena in spin-chain compound Er₂BaNiO₅

Abstract

The Haldane spin-chain compound Er2BaNiO5 has been known to possess magnetoelectric coupling below the magnetic ordering temperature. Here we report various low-temperature magnetic and magnetocaloric properties, and magnetodielectric effect above magnetic ordering temperature in this compound. The present compound displays a coexistence of conventional and inverse magnetocaloric effects with a large entropy change of 5.9 and −2.5 J/kg K, respectively. Further, it exhibits a remarkable switching between them, which can be tuned with temperature and magnetic field. In addition, evolution of two magnetic field-dependent metamagnetic transitions at 19.7 and 27.7 kOe, and their correlation with magnetocaloric switching effect, make this compound effective for potential applications. On the other hand, demonstration of intrinsic magnetodielectric effect (1.9%) near and above antiferromagnetic ordering temperature, through a moderate coupling between electric dipoles and magnetic spins, establishes this compound as a useful candidate for future research. A detailed analysis of these findings, in a framework of different magnetic interactions and magnetocrystalline anisotropies, is discussed here. Overall, these results may provide a future pathway to tune the magnetic, magnetodielectric, and magnetocaloric properties in this compound toward better application potential.

Correlation between linear magnetostriction and magnetocaloric effect in the Fe7Se8 single crystals

“…The correlation effects arise here because of a specific mechanism of magnetoresistance in manganites related to the suppression of carrier spin-disorder scattering, which is directly related to magnetic entropy. A different mechanism responsible for the correlation effect was recently discovered in the Haldane spin-chain compound Er 2 BaNiO 5 [3]. In this material, two magnetic-fielddependent metamagnetic transitions have been shown to be correlated with the magnetocaloric switching effect.…”