Influence of chemical substitution and sintering temperature on the structural, magnetic and magnetocaloric properties of La1-xSrxMn1-yFeyO3

TL;DR

This study investigates how chemical substitution and sintering temperature influence the structural, magnetic, and magnetocaloric properties of La1-xSrxMn1-yFeyO3, aiming to optimize room-temperature magnetic cooling applications.

Contribution

It demonstrates that sintering temperature and chemical doping can be used to control the magnetic transition and enhance the magnetocaloric effect in manganite ceramics.

Findings

Curie temperature can be tuned close to room temperature.

Magnetic entropy change peaks near the Curie temperature.

Disorder from doping broadens the temperature range of the magnetocaloric effect.

Abstract

The effects of sintering temperature (Ts) and chemical substitution on the structural and magnetic properties of manganite compounds La1-xSrxMn1-yFeyO3 (0.025 <= x <= 0.7; y= 0.01,0.15) are explored in a search to optimize their magnetocaloric properties around room temperature. A ferromagnetic (FM) to paramagnetic (PM) phase transition is observed at a Curie temperature Tc that can be controlled to approach room temperature by Sr and Fe substitution, but also by adjusting the sintering temperature Ts. Accordingly, the magnetic entropy change (-DSM) quantifying the magnetocaloric effect (MCE) presents a peak at or close to Tc that shifts and broadens with both Sr and Fe doping and is further tuned with sintering temperature. Altogether, we show that it is possible to adjust the strength and dominance of the ferromagnetic coupling in these ceramics, but also using disorder as a tool to broaden and adjust the temperature range with significant magnetic entropy change.