Spin-polarized electric current in Cd$_{48.6}$Mn$_{11.4}$As$_{40}$ nanocomposite

The temperature dependences of electrical resistivity and magnetization have been measured in the Cd$_{48.6}$Mn$_{11.4}$As$_{40}$ nanocomposite in the temperature range 10–350 K. It is shown that the electrical properties of Cd$_{48.6}$Mn$_{11.4}$As$_{40}$ are due to spin-polarized electrons injected from ferromagnetic MnAs nanoclusters inward the Cd$_3$As$_2$ matrix. If the magnetic ordering among nanoclusters increases, the spin-polarized current increases as well. In addition, an increase in the concentration of intrinsic carriers in the host matrix leads to an increase in the spin-polarized current also. This concept is confirmed by measurements of current-voltage characteristics (CVC) at the temperatures: a) below the critical temperature of formation of cluster glass $T_{cg}$ = 241 (i.e. at 77 and 172 K) b) and above it (i.e. at 273.15 and 373.15 K), which exhibit a deviation from ohmicity, increasing with voltage. This means that the greater is the spin polarization of intrinsic electrons in Cd$_3$As$_2$, due to an increase in the injection of spin-polarized electrons from MnAs with voltage, the higher is the current.