Magnetic behavior of Mn3GaC under high magnetic field and high pressure

We have measured the magnetization and magnetostriction of Mn3GaC in pulsed high magnetic fields up to 37T and the magnetization under steady magnetic field and pressure up to 0.82 GPa. Mn3GaC is antiferromagnetic (AF) at low-temperatures. It exhibits successive transitions to an intermediate (I); to a ferromagnetic (F) and to a paramagnetic phase. The transition between the AF and I phases is first order and the others are second order. The transition temperature between the I and F phases does not change greatly with increasing magnetic field. At low temperatures, a metamagnetic transition from the AF to the I state is observed. Volume magnetostriction measurement at 4.2 K indicates that the volume is abruptly decreased by the metamagnetic transition and then gradually shrinks with increasing field. High pressure stabilizes the F phase and enhances the Mn moment.