Rapid Microwave Preparation and Composition Tuning of the High-Performance Magnetocalorics (Mn,Fe)2(P,Si)

Published: February 28, 2018

Author(s)

Jason H. Grebenkemper, Joshua D. Bocarsly, Emily E. Levin, Gareth Seward, Colin A Heikes, Craig Brown, Sumohan Misra, Fabian Seeler, Kerstin Schierle-Arndt, Stephen D. Wilson, Ram Seshadri

Abstract

A rapid preparation utilizing assisted microwave heating has been developed for (Mn,Fe)2(P,Si) and used to prepare samples of (Mn,Fe)2-δPd0.5^Si0.5 with δ=0, 0.06, and 0.12. To fully understand the effects of processing and composition changes on structure and properties, these materials were characterized using synchrotron powder diffraction, neutron powder diffraction, electron microprobe analysis (EMPA), X-ray fluorescence (XRF), and magnetic measurements. The diffraction experiments reveal that increasing δ results in decreasing amounts of the common (Mn,Fe)3Si impurity. EMPA shows (Mn,Fe)2(P,Si) in all three samples to be Mn and P rich, while XRF demonstrates that the bulk material is Mn rich yet P deficient. Increasing δ brings the Mn:Fe and P:Si ratios closer to their starting values. Magnetization measurements show an increase in saturation magnetization and ordering temperature with increasing δ, consistent with the increase in Fe and Si content. Increasing δ also results in a decrease in {Δ}Thys and increase in {Δ}SM.
Citation: ACS Applied Materials and Interfaces
Volume: 10
Issue: 8
Pub Type: Journals

Keywords

Magnetocalorics, Microwave Synthesis, Neutron Diffraction, synchrotron diffraction
Created February 28, 2018, Updated November 10, 2018