Magnetic properties of the MnBi intermetallic compound

A MnBi alloy containing over 90 wt % low-temperature phase (LTP) has been o btained by high-temperature sintering and magnetic purification. The coerci vity of the bonded MnBi magnet increases with increasing temperatures. A co ercivity of 2.0 T has been achieved at 400 K. The maximum energy product (B H)(max) of the magnet is 7.7 MGOe (61 kJ/m(3)) and 4.6 MGOe (37 kJ/m(3)) at room temperature. and 400 K, respectively. Neutron diffraction and magneti c data reveal a spin reorientation, which gives rise to low anisotropy fiel ds and coercivity at lower temperatures for the LTP MnBi alloy. (C) 2001 Am erican Institute of Physics.