Broadening of magnetocaloric effect at elevated temperatures in nanocrystalline ZnFe₂O₄ thin films

TY - JOUR

T1 - Broadening of magnetocaloric effect at elevated temperatures in nanocrystalline ZnFe2O4 thin films

AU - Bohra, Murtaza

AU - Singh, Nitesh

AU - Vittal Battula, Sai

AU - Singh, Vidyadhar

AU - Annadi, Anil

AU - Toulkeridou, Evropi

AU - Grammatikopoulos, Panagiotis

N1 - Publisher Copyright: © 2024

PY - 2024/2

Y1 - 2024/2

N2 - The detection and characterization of the Magnetocaloric Effect (MCE) at the nanoscale and its subsequent impact on next-generation cooling on-chip devices are of paramount importance. Here, we demonstrate that the MCE properties housed within a ferrimagnetic phase arise in disordered ZnFe2O4. The robustness of the MCE in terms of magnetic entropy change ΔSmax (=0.07–0.09 J/kg-K at 0.5 T) emerges in ZnFe2O4 thin films at larger temperature ranges 425–710 K, reaching above room temperature. By fitting the magnetization vs. temperature curves with a Gaussian-type distribution, we observed a correlation between the broadening of the MCE peak, Curie temperature (TC) distribution, and grain size distributions in nanocrystalline ZnFe2O4 thin films. The width of TC distributions increases (up to 150 K) and consequently, the ΔS curves show an extended full width at half maximum, resulting in larger relative cooling power (RCP), and a wider change in specific heat capacities (ΔCP) and adiabatic temperatures (ΔTad). This study reveals that tuning the relative strengths of the sublattice spin configuration of antiferromagnetic (AFM) ZnFe2O4 through in-situ and ex-situ heat treatment paves the way for the alteration of MCE properties.

AB - The detection and characterization of the Magnetocaloric Effect (MCE) at the nanoscale and its subsequent impact on next-generation cooling on-chip devices are of paramount importance. Here, we demonstrate that the MCE properties housed within a ferrimagnetic phase arise in disordered ZnFe2O4. The robustness of the MCE in terms of magnetic entropy change ΔSmax (=0.07–0.09 J/kg-K at 0.5 T) emerges in ZnFe2O4 thin films at larger temperature ranges 425–710 K, reaching above room temperature. By fitting the magnetization vs. temperature curves with a Gaussian-type distribution, we observed a correlation between the broadening of the MCE peak, Curie temperature (TC) distribution, and grain size distributions in nanocrystalline ZnFe2O4 thin films. The width of TC distributions increases (up to 150 K) and consequently, the ΔS curves show an extended full width at half maximum, resulting in larger relative cooling power (RCP), and a wider change in specific heat capacities (ΔCP) and adiabatic temperatures (ΔTad). This study reveals that tuning the relative strengths of the sublattice spin configuration of antiferromagnetic (AFM) ZnFe2O4 through in-situ and ex-situ heat treatment paves the way for the alteration of MCE properties.

KW - Cation disorder

KW - Curie temperature

KW - Magnetocaloric effect

KW - ZnFeO thin films

UR - http://www.scopus.com/inward/record.url?scp=85184473924&partnerID=8YFLogxK

U2 - 10.1016/j.rinp.2024.107382

DO - 10.1016/j.rinp.2024.107382

M3 - 文章

AN - SCOPUS:85184473924

SN - 2211-3797

VL - 57

JO - Results in Physics

JF - Results in Physics

M1 - 107382

ER -