Influence of the magnetic field on transport properties of holmium - manganese sulfide

Holmium-manganese sulfide with giant magnetoresistance refers to new magnetic sulfide compounds of holmium and manganese that have the effect of giant magnetoresistance (i. e., with special magnetoelectric properties), which can be used as components of sensor technology, magnetic memory, and spintronics. The technology of manufacturing polycrystals HoXMn1-XS grown by crystallization from the melt of the obtained powdered sulfides with a purity not lower than 99,9 %, in glass-carbon crucibles and a quartz reactor in an argon atmosphere is presented. According to the results of x-ray diffraction analysis, HoXMn1-XS holmium-manganese sulfides have a HCC structure of the NaCl type. As the degree of cationic substitution increases, the unit cell parameter increases linearly with the concentration. No concomitant impurity phases are detected in the synthesized samples. To determine the state of the spin glass, magnetic moment measurements are conducted at several frequencies ω = 1 kHz, 10 kHz and 100 kHz. The dependence of magnetic characteristics on the frequency of measurements is found. The damping of the magnetic moment and its increase with a decrease in temperature is reviled, which is connected with the formation of metastable States. Measurements of electrical resistance without a field and in a magnetic field are conducted. Anomalies in the temperature dependence of the conductivity are found. A change in the magnetoresistance sign is detected with the increase of temperature below and above room temperature.