Rotating magnetocaloric effect in first-order phase transition material Gd5Si2Ge2

Abstract

The rotating magnetocaloric effect (RMCE) induced by self-demagnetization has been investigated in the giant magnetocaloric effect (GMCE) material Gd 5 Si 2 Ge 2 . This shape-dependent effect had thus far only been reported in pure Gd, marking this as the first analysis of the effect in a sample with a magnetostructural first-order phase transition. By rotating the applied magnetic field vector while keeping its intensity constant, the demagnetizing field within a high aspect ratio sample changes significantly, leading to an RMCE. We characterize RMCE by determining the adiabatic temperature change ( Δ T a d r o t ) directly through temperature measurements, and the isothermal entropy change ( Δ S M r o t ) via magnetometry and magnetostatic simulations. We obtain a remarkable maximum Δ T a d r o t of 1.77 K for a constant external field of 0.8 T, higher than that obtained under 1.0 T. The magnetostatic simulations not only corroborate the highly non-monotonous field-dependence of | Δ S M r o t | , which reaches 95% of its maximum value at 0.8 T, 6.12 J K −1 kg −1 for the experimentally measured shape, but also estimate a 35% increase in the maximum | Δ S M r o t | up to 8.67 J K −1 kg −1 in a simulated shape with higher aspect ratio.

The authors' abstract, as published at the source. Journal of Alloys and Compounds, 2026 · DOI ↗