Anisotropy Properties of Mn_2P Single Crystals with Antiferromagnetic Transition

Single crystals of hexagonal structure Mn_2P are synthesized by Sn flux for the first time. Transport and magnetic properties have been performed on the single crystals, which is an antiferromagnet with Neel temperature 103 K. Obvious anisotropy of resistivity is observed below the Neel temperature, which is manifested by metallic behavior with a current along the c-axis and semiconducting behavior with a current along the a-axis. The negative slope of temperature-dependent resistivity is observed above the Neel temperature in both a and c directions. Strong anisotropy of magnetic susceptibility is also evident from the magnetization measurements. A weak metamagnetic transition is observed only in a-axis plane at high magnetic field near 50–60 K compared to the c-axis. We believe these strong anisotropies of magnetic and transport properties are due to the anisotropy of spin arrangement. Mn_2P could be a candidate for exploration of possible superconductivity due to the low spin state.