Cu-Mn: Atomic short-range order, spin-density wave, and spin glass.

Abstract

Using a specimen with well-developed atomic short-range order (ASRO), the magnetism of a Cu-Mn alloy was studied by use of a neutron-scattering method. A spin-density wave (SDW) with high Ne\ifmmode\acute\else\textasciiacute\fi{}el temperature (${\mathit{T}}_{\mathit{N}}$\ensuremath{\sim}400 K) was observed. The SDW propagates on the ab plane of the well-developed ASRO, which is accompanied by a tetragonal lattice distortion. The type of ASRO, the spin structure of the SDW, and the origin of the spin-glass-like behavior in ordinary Cu-Mn alloys are discussed on the basis of the present experimental data.