Pressure effect on the anomalies of the electric and magnetic properties of diluted magnetic semiconductor CdGeAs2 doped with Mn



This paper presents the results of the high pressure (up to 7 GPa) effect on the diluted magnetic semiconductor (DMS) CdGeAs2: Mn with x = 0.06–030. The normal R0 and anomalous RS portions of the Hall coefficients have been determined from the magnetic field dependencies of the Hall resistance. Pressure ranges related to the anomalies of the electric and magnetic properties have been found and studied. It has been shown that structural phase transitions are observed on the baric dependencies and their transition point shifts depending on the Mn content.

The first- and second-order phase transitions (ferromagnetic–paramagnetic and paramagnetic–paramagnetic) have been identified on the magnetic susceptibility dependence in the pressure areas of P > 1.3 GPa and P ≈ 4 GPa which can be explained by occurrence of the second phase of MnAs in the basic structure of CdGeAs2. Positive (PMR) and negative magnetoresistance (NMR) induced by high pressure also takes place in all the compounds studied.