Pyroelectric Control of Spin Polarization Assisted Coexistence of Giant Positive and Negative Magnetocaloric Effects

TL;DR

This paper demonstrates how pyroelectric control in layered nanostructures enables the coexistence of positive and negative magnetocaloric effects through magneto-pyroelectric coupling, without the need for electric fields.

Contribution

It introduces a novel method to achieve giant magnetocaloric effects by leveraging pyroelectric control in layered nanostructures, bypassing traditional electric field requirements.

Findings

Giant MCE achieved via magneto-pyroelectric coupling.

Coexistence of positive and negative MCE in PZT/CFO/PZT structures.

Large entropy changes comparable to existing giant MCE values.

Abstract

Electric field control of magnetism is the key to many next generation spintronics applications1. Ferroelectric control of spin polarization2,3 followed by the electrically driven repeatable magnetization reversal in the absence of applied magnetic field4 have proven to be the milestones in this direction. This article propose how these phenomena could be utilized in a reverse manner to gain control over magnetization even in the absence of electric field. In turn, coexistence of positive5 as well as negative6 magnetocaloric effect (MCE) is attained in tri-layered PbZr0.53Ti0.47O3-CoFe2O4-PbZr0.53Ti0.47O3 (PZT/CFO/PZT) nanostructures for identical temperature ranges when subjected to different applied magnetic fields. Unlike conventional approaches5-9 the present study demonstrate that it is possible to obtain giant MCE merely by magneto-pyroelectric coupling. Consequently, the MCE entropy changes calculated using Maxwell equations are found to be as large as reported for existing giant MCE values6,9,10.