Influence of anionic substitution on the magnetic-resistance properties of the manganese chalkogenides

The paper describes the materials on the basis of solid solutions GdxMn1-xS и GdxMn1-xSe with concentration x = 0.2, which could potentially be used as sensors, sensor devices, read-write information. The magnetoresistive properties of Gd0.2Mn0.8S and Gd0.2Mn0.8Se solid solutions in a zero and magnetic field of 13 kOe in the temperature range 80-500 K were studied. In manganese sulphides GdxMn1-xS, the sign of the magnetoresistance changes from positive to negative and its maximum in the region of transition to the magnetically ordered state. The minimum is found at T = 325 K, and in the magnetic field the resistance also increases, and the minimum in its temperature dependence shifts toward high temperatures to T = 380 K. The magnetoresistance changes sigh with increasing temperature from positive to negative at T = 320 K and disappears at T = 475 K. In manganese sulfides GdxMn1-xSe, a negative magnetoresistance is observed below room temperature and a hysteresis of the current-voltage characteristics. In a magnetic field the hysteresis decreases. The change of the sign magnetoresistance with increasing temperature is established. The magnetoresistance δ = (ρ(H) - ρ(0)) / ρ(0) in GdxMn1-xSe with replacement concentration x = 0.2 changes sigh with increasing temperature at T = 320 K. At this temperature, a wide hysteresis of the current-voltage characteristic is observed. The synthesis of new chalcogenide compounds in the cationic substitution of manganese by gadolinium in the MnS and MnSe systems will make it possible to clarify the effect of the anion system, as a result of studying its magnetoresistive properties with a concentration in the gadolinium ion flux region along the x = 0.2 lattice. The experimental data are explained in the model of the orbital ordering and spin-orbit interaction.