Spin-glass ordering in the diluted magnetic semiconductor Zn1-xMnxTe

We have performed both ac susceptibility and de magnetization measurements on the diluted magnetic semiconductor Zn1-xMnxTe. The measurements clearly indicate spin-glass behavior. For samples with concentrations x= 0.51 and x =0.41, the data for the imaginary part of the complex susceptibility (chi " ) were analyzed according to conventional power-law dynamics and good scali ng was obtained with the critical exponent values z nu= 10+/-2 and beta= 1. 0+/-0.2. These values of z nu and beta are consistent with results obtained in other insulating spin-glass systems with short-range interactions. Beca use of the presence of significant Dzyaloshinsky-Moriya anisotropy in these materials, an attempt was also made to fit the data using an activated dyn amics model. However, the scaling of the chi " data was less satisfactory i n this case. Magnetization measurements on the x= 0.51 sample also showed a spin-glass-like transition. Scaling of the nonlinear magnetization just ab ove the transition gave T-c=20.8+/-0.2 K, and the critical exponent values gamma=4.0+/-1.0 and beta = 0.8+/-0.2. The value of T-c obtained from the st atic magnetization measurements is in good agreement with the value T-c=20. 7+/-0.05 K obtained from the dynamic scaling analysis. Further, the value f or the critical exponent gamma obtained in this work is in fair agreement w ith values reported for other spin-glass materials. These results represent convincing evidence that diluted magnetic semiconductors are a subset of t he class of insulating spin-glass materials with short-range interactions. [S0163-1829(98)02743-X].