A magnetocaloric study on the series of 3d-metal chromites ACr$_{2}$O$_{4}$ where A = Mn, Fe, Co, Ni, Cu and Zn

TL;DR

This study investigates the magnetic and magnetocaloric properties of 3d-metal chromites ACr₂O₄ with various A-site ions, revealing how magnetic moments influence the magnetocaloric effect and analyzing the nature of their phase transitions.

Contribution

It provides a comprehensive magnetocaloric analysis of ACr₂O₄ chromites with different A ions, highlighting the relationship between magnetic moments and MCE, and exploring phase transition characteristics.

Findings

MCE magnitude decreases with lower A-site magnetic moments, except for CuCr₂O₄.

Scaling analysis reveals the order and nature of phase transitions.

Magnetic and magnetocaloric behaviors vary with different A-site ions.

Abstract

The 3d-metal chromites ACr$_2$O$_4$ where A is a magnetic ion, show the paramagnetic to ferrimagnetic phase transition at T$_C$ while for non-magnetic A-site ion, ACr$_2$O$_4$ show paramagnetic to antiferromagnetic phase transition at T$_N$. In this report, we present the detailed study of magnetic and the magnetocaloric effect (MCE) of the 3d-metal chromites ACr$_{2}$O$_{4}$ (where A = Mn, Fe, Co, Ni, Cu, and Zn) near T$_C$ and T$_N$. We find the magnitude of MCE (-$\Delta$S$_M$) decreases on decreasing the magnetic moment of A-site ion with an exception for CuCr$_{2}$O$_{4} $. Additionally, to know more about the order and nature of phase transition, we have made a scaling analysis of (-$\Delta$S$_{M}$) for all the chromites across the phase transition temperatures T$_C$ and T$_N$.