Some structural and magnetic properties of Mn1 + ΔAs1−xPx single crystals

Abstract

Lattice parameters and magnetic anisotropy of MnAs1−xPx single crystals with a nominal composition between 5 and 20 at% P are presented; samples are taken from two different growth apparatus. The magnetic phenomena suggest that distributions of exchange couplings are introduced. The generating random element of the lattice appears to be a displacement disorder of the Mn(As) atoms which might be a consequence of the anion mixture As/P and/or non‐stoichiometry. The susceptibility anomaly at Tt which so far has been ascribed to a second‐order NiAs‐MnP displacive phase transition might alternatively be due to a magneto‐volume effect which is linked to the exchange coupling distribution, at least for the mixed or non‐stoichiometric crystals.