Magnetic Circular Dichroism in Cr-doped CdMnTe

Abstract

We have investigated the magneto-optical properties of 1% Cr-doped CdMnTe, known to be a diluted magnetic semiconductor (DMS), grown by using the vertical Bridgman method. From the Faraday rotation measurements, the Verdet constant for Cd 0.62Mn 0.37Cr 0.01Te was -0.93 deg/cm • G at 625 nm (T = 10 K), which is in a direction opposite to that for a nonmagnetic material, and was enhanced, compared to the value for CdMnTe, by an addition of the Cr magnetic ion. Also, the magnetic circular dichroism (MCD) spectral shape, which is directly related to the Zeeman splitting of the band structure caused by the sp-d exchange interaction, indicated that Cr-doped CdMnTe was a DMS, instead of the magnetic precipitate, and had a weak ferromagnetic ordering.