# Dynamics of the magnetoelastic phase transition and adiabatic temperature change in Mn1.3Fe0.7P0.5Si0.55

## TL;DR

This study investigates the magnetoelastic phase transition and adiabatic temperature change in a Mn-Fe-P-Si alloy, revealing rate-independent effects and complex hysteresis behavior under varying magnetic field sweep rates.

## Contribution

It provides new insights into the dynamics of the magnetoelastic phase transition and the limitations of phase change completion at high magnetic fields.

## Key findings

- Magnetocaloric effect remains consistent across different field-sweep rates.
- First-order phase transition does not fully complete even at 20 T.
- Hysteresis in temperature change depends on the magnetic field sweep rate.

## Abstract

The adiabatic temperature change DTad of a Mn1.3Fe0.7P0.5Si0.55 Fe2P-type alloy was measured under different magnetic field-sweep rates from 0.93 Ts-1 to 2870 Ts-1. We find a field-sweep-rate independent magnetocaloric effect due to a partial alignment of magnetic moments in the paramagnetic region overlapping with the magnetocaloric effect of the first-order phase transition. Additionally, the first-order phase transition is not completed even in fields up to 20 T leading to a non-saturating behavior of DTad. Measurements in different pulsed fields reveal that the first-order phase transition cannot follow the fast field changes as previously assumed, resulting in a distinct field-dependent hysteresis in DTad.