Weak ferromagnetism in CdMnZnTe single crystal

Abstract

We studied the magnetic properties of diluted magnetic semiconductors Cd0.65-yMn0.35Zny Te single crystals grown using a vertical Bridgman method. The Cd0.65-yMn0.35Zny Te crystals with various Zn mole fractions have been grown in the zinc-blende structure. The band-gap energy obtained from the optical absorption spectrum at 300 K is linearly increased with increasing the addition of Zn into CdMnTe, which may be due to a decrease in the lattice constant. We have observed that the Cd0.22Mn0.35Zn0.43Te crystal showed weak ferromagnetic ordering up to 300 K, and the coercive field was 25 Oe at 250 K. The magnetic moment showed a maximum for the sample with y = 0.43, and the value was approximately ten times larger than that of the Cd0.65Mn0.35Te crystal. This result reflects that Zn ion mediates and enhances the spin-spin interaction between Mn2+ ions with increasing Zn composition up to y = 0.43.