Stabilization of the high-temperature phase of MnBi by the addition of rhodium or ruthenium

It has been found that adding Rh or Ru to MnBi is effective in stabilizing the high-temperature β phase (distorted NiAs structure) relative to the low-temperature α phase (undistorted NiAs structure). This effect has been observed in both evaporated thin films and bulk samples. Addition of 1 at.% Rh to bulk MnBi increases the minimum time constant for the β→α transformation by 5 orders of magnitude. Stabilization is important in the use of MnBi for thermomagnetic recording.