Magnetic Phase Diagram of Solid Solutions in the CoCr 2 S 4 –Cu 0.5 Ga 0.5 Cr 2 S 4 System

The magnetic phase diagram of solid solutions in the CoCr 2 S 4 –Cu 0.5 Ga 0.5 Cr 2 S 4 system was constructed. The widest concentration range (0.38 < x < 1) in the diagram represents solid solutions based on the ferrimagnetic semiconductor CoCr 2 S 4 ( T C = 223 K), which exhibits unusual properties in the magnetic ordering region while measuring the temperature dependence of the dynamic susceptibility. The magnetic properties were studied with a Quantum Design PPMS-9 platform within the temperature range 5–300 K in a 100-Oe constant magnetic field and/or a varying (100-, 500-, and 1000-Hz) magnetic field with an amplitude of 1 Oe.