High temperature magnetic order in Zn1−xMnxSnSb2+MnSb nanocomposite ferromagnetic semiconductors

Abstract

We present studies of structural, magnetic, and electrical properties of Zn1−xMnxSnSb2+MnSb nanocomposite ferromagnetic semiconductors with the average Mn-content, , changing from 0.027 up to 0.138. The magnetic force microscope imaging done at room temperature shows the presence of a strong signal coming from MnSb clusters. Magnetic properties show the paramagnet-ferromagnet transition with the Curie temperature, TC, equal to about 522 K and the cluster-glass behavior with the transition temperature, TCG, equal to about 465 K, both related to MnSb clusters. The magnetotransport studies show that all investigated samples are p-type semiconductors with high hole concentration, p, changing from 1021 to 1022 cm−3. A large increase in the resistivity as a function of the magnetic field is observed at T < 10 K and small magnetic fields, mT, for all the studied samples with a maximum amplitude of the magnetoresistance about 460% at T = 1.4 K. The large increase in the resistivity is most probably caused by the appearance of the superconducting state in the samples at T < 4.3 K.