The nonlinear ac susceptibility ${\mathrm{\chi }}_{\mathrm{nl}}^{\prime }$ of the short-range Ising spin glass ${\mathrm{Fe}}_{0.5}$${\mathrm{Mn}}_{0.5}$${\mathrm{TiO}}_3$ has been measured using a superconducting-quantum-interference-device magnetometer. The spin-glass temperature, ${\mathrm{T}}_{\mathrm{g}}$, and the critical exponent γ were estimated from the temperature dependence of the quadratic field term of ${\mathrm{\chi }}_{\mathrm{nl}}^{\prime }$, yielding ${\mathrm{T}}_{\mathrm{g}}$=20.70 and γ=4.0. Static-scaling analyses, using different scaling equations, gave similar results. Using γ and results from previous dynamic-scaling analyses, a number of critical exponents have been obtained through different scaling relations, e.g., δ=8.4 and ν=1.7. The results support the existence of a finite-temperature phase transition in a three-dimensional Ising spin glass.

• Received 22 May 1990

DOI:https://doi.org/10.1103/PhysRevB.43.8199