Inhomogeneous Cr distribution and superparamagnetic behavior in magnetic semiconductor (Zn, Cr)Te

The correlation between Cr spatial distribution and magnetic properties have been investigated for Zn1‐xCrxTe films with low and high average Cr contents of x ≅ 0.05 and 0.2, which were grown by MBE under different Zn/Te flux or with the co‐doping of donor impurity iodine. The EDS analysis reveals that the Cr distribution is strongly inhomogeneous in films grown under the Zn‐rich condition or co‐doped with iodine, in contrast to relatively homogeneous distribution in undoped films grown in the Te‐rich condition. In the magnetization measurements, the superparamagnetic features, such as the blocking phenomena in the temperature dependence of magnetization, become more pronounced with the enhancement of inhomogeneity of Cr distribution.