Measurements of the nonlinear susceptibility, irreversibility onset, and relaxation of the remanent magnetization are reported for a single-crystal sample of Y${\mathrm{Tb}}_{3\mathrm{at}.\mathrm{\%}}$. The data give strong support for the existence of a spin-glass phase transition for spin components in the basal plane, but not for those along the c axis. A scaling analysis of the nonlinear susceptibility leads to the values δ=3.2±0.2 and φ=3.0±0.2 for the field and cross-over exponents, respectively. These values are consistent with the position of the de Almeida–Thouless line observed below the freezing temperature.

• Received 12 August 1985

DOI:https://doi.org/10.1103/PhysRevB.32.7425