High-pressure growth and characterization of bulk MnAs single crystals

Abstract

Bulk single crystals of manganese arsenide (MnAs) were grown from melt at 1 GPa and 1100 {\deg}C by using a cubic-anvil, high-pressure, and high-temperature technique. The as-grown black colored crystals extracted from solidified lump exhibit a plate-like morphology, with flat surfaces and maximum dimensions up to ~ 3 x 2 x 0.5 mm3. The hexagonal crystal structure at room temperature was confirmed by X-ray diffraction [B81, space group P63/mmc, No 194, Z = 2, a = 3.7173(4) {\AA}, b = 3.7173(4) {\AA}, c = 5.7054(8) {\AA}, and V = 68.277(16) {\AA}3]. Temperature-dependent magnetization measurements reveal the occurrence of a first-order ferro- to paramagnetic transition at Tc = 318.5 K accompanied by a hysteresis of ~ 9 K. The successful growth of relatively large crystals reported here might be extended to various substituted analogues of MnAs, thus opening new possibilities for further exploration of this interesting system.