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arXiv · 1708.09554

Mechanism of magnetostructural transformation in multifunctional Mn$_3$GaC

E. T. Dias·K. R. Priolkar·R. Ranjan·A. K. Nigam·S. Emura
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Abstract

Mn$_3$GaC undergoes a ferromagnetic to antiferromagnetic, volume discontinuous cubic-cubic phase transition as a function of temperature, pressure and magnetic field. Through a series of temperature dependent x-ray absorption fine structure spectroscopy experiments at the Mn K and Ga K edge, it is shown that the first order magnetic transformation in Mn$_3$GaC is entirely due to distortions in Mn sub-lattice and with a very little role for Mn-C interactions. The distortion in Mn sub-lattice results in long and short Mn-Mn bonds with the longer Mn-Mn bonds favoring ferromagnetic interactions and the shorter Mn-Mn bonds favoring antiferromagnetic interactions. At the first order transition, the shorter Mn-Mn bonds exhibit an abrupt decrease in their length resulting in an antiferromagnetic ground state and a strained lattice.

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E. T. Dias, K. R. Priolkar, R. Ranjan, A. K. Nigam, S. Emura. 2017-08-31. Mechanism of magnetostructural transformation in multifunctional Mn$_3$GaC. https://doi.org/10.1063/1.4996933

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