Magnetocaloric effect near room temperature in chromium telluride (Cr2Te3)

TL;DR

This study investigates the magnetocaloric effect of chromium telluride (Cr2Te3) near room temperature, demonstrating its potential for magnetic refrigeration with significant entropy change and stable composition, supported by experimental and theoretical analysis.

Contribution

The paper presents the first comprehensive experimental and theoretical analysis of Cr2Te3's magnetocaloric properties near room temperature, highlighting its advantages over existing materials.

Findings

Cr2Te3 exhibits a large magnetic entropy change of 2.36 J/kg-K at 0.1 T.

Refrigeration capacity of 160 J/kg was achieved, comparable to other Cr compounds.

First-principles calculations confirmed magnetic transition temperatures and structural changes.

Abstract

Transition metal telluride compositions are explored extensively for their unique magnetic behavior. Since chromium telluride (Cr2Te3) exhibits a near-room-temperature phase transition, the material can be effectively used in applications such as magnetic refrigeration. Compared to existing magnetocaloric materials, Heusler alloys, and rare-earth-based alloys, the large-scale synthesis of Cr2Te3 involves less complexity, resulting in a stable composition. Compared to existing tellurides, Cr2Te3 exhibited a large magnetic entropy change of 2.36 J/kg-K at a very small magnetic field of 0.1 T. The refrigeration capacity (RC) of 160 J/kg was determined from entropy change versus temperature curve. The results were comparable with the existing Cr compounds. The telluride system, Cr2Te3 compared to pure gadolinium, reveals an enhanced room temperature magnetocaloric effect (MCE) with a broad working temperature range. The heating cycle of MCE was successfully visualized using a thermal imaging setup. To confirm the observed magnetic properties of Cr2Te3, first-principles calculations were conducted. Through density functional theory (DFT) studies, we were able to determine both Curie temperature (TC) and Neel temperature (TN) which validated our experimental transitions at the same temperatures. Structural transition was also observed using first principles DFT calculation which is responsible for magnetic behavior.