Abstract
MnPtGa crystallizes in the hexagonal structure type in space group and has been reported to display a ferromagnetic Curie temperature near 220K. Here we find a transition near K to a ferromagnetic state, albeit with a reduced moment from what is expected for collinear ordering. The peak magnetocaloric entropy change was determined to be for an applied magnetic field of at the ferromagnetic ordering temperature. Magnetostructural coupling manifests as a change in the slope of the thermal expansion coefficients of the lattice parameter near , with a negative spontaneous volume magnetostriction; ppm at 190K. Neutron powder diffraction studies of the magnetic ground state reveal an evolution in complexity as temperature decreases: from a ferromagnet, to a canted antiferromagnet, to the eventual formation of a spin-density-wave state at low temperatures.
3 More- Received 6 July 2019
- Revised 18 February 2020
- Accepted 17 March 2020
DOI:https://doi.org/10.1103/PhysRevMaterials.4.044405
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