Magnetism of frustrated Tb$_{2}$CuIn$_{3 }$by $\mu $SR

The magnetic properties of Tb$_{2}$CuIn$_{3}$ differ markedly form those of other R$_{2}$CuIn$_{3}$ alloys. Neutron scattering data were interpreted in terms of the formation of a spin-glass-like state at 45K which coexists below T$_{N}$= 33K with long-range antiferromagnetic order. The origin of this unusual magnetic behaviour is thought to arise from frustration due to competing antiferromagnetic nearest neighbour and ferromagnetic next-nearest neighbour exchange together with structural disorder. The present $\mu $SR data definitely confirm spin glass magnetism below 45K. At 33K a second $\mu $SR signal appears which is compatible with long-range magnetic order. It shows, however, that the antiferromagnetic state is characterized by strong short range (over a few lattice distances) spin disorder.