Magnetic properties of Mn1-xGdxSe solid solutions

Study of the materials for spintronics operating under extreme conditions based on manganese selenides substituted with gadolinium are investigated. The technology of synthesis of solid solutions based on solid-phase reactions using MnSe and GdSe compounds is presented. As a result, Mn1-xGdxSe solid solutions with concentrations x = 0.05; 0.1; 0.15 and 0.5 were synthesized. The synthesis was carried out under vacuum conditions of 10-2 Pa. The products of the primary synthesis were subjected to thorough grinding into powders, from which tablets were made under pressure for homogenizing annealing at 1370 K. After two hours of exposure, the synthesis products were tempered in cold water. At the final stage, homogeneous strong ingots of grayish-silver color were obtained. X-ray phase analysis of synthesized solid solutions of the Mn1-xGdxSe system was performed in Cu-K a radiation in the point-by-point measurement mode with a scanning step along the angle Δ2θ = 0,03 degree, the time of information collection at the reference point Δτ =3 seconds. The spatial symmetry group and the parameter of the elementary crystal cell of solid solutions of the Mn1-xGdxSe system from X-ray diffraction analysis are determined. The dependence of the parameter value of the crystal lattice of solid solutions on the concentration of gadolinium ions is found. The specific magnetization was measured by the ponderomotor method in a magnetic field with an induction of B = 0.86 Tesla and the magnetic susceptibility of the samples was determined in the temperature range of 80 ≤ T ≤ 950 K. The cycles carried out in the heating - cooling mode did not detect a change in properties. The Neel temperatures and the paramagnetic Curie temperature are determined from the Curie - Weiss law depending on the concentration of a rare earth element. A decrease in the temperature of the magnetic phase transition is established.