ROOM TEMPERATURE FERROMAGNETISM IN NOVEL DILUTED MAGNETIC SEMICONDUCTOR Cd1-xMnxGeP2

High concentration of Mn atoms has been incorporated in the surface region of II-IV-V2 type chalcopyrite semiconductor CdGeP2. Photoluminescence spectrum at 20 K shows a peak around 3.2 eV, suggesting that the incorporation of Mn introduces an energy gap much higher than that of the host semiconductor (1.83 eV). Prominent magnetic hysteresis loops with coercivity of 0.5 kOe has been observed at RT. Magnetic force microscope measurements reveal a stripe-shaped domain pattern on the top surface. Magneto-optical Kerr ellipticity spectrum measured at RT show a prominent peak at 1.7 eV and a broad tail up to 3.5 eV. Authors tentatively attribute the ferromagnetism to the double exchange interaction between Mn2+ and Mn3+ states due to the structural feature of II-IV-V2 type chalcopyrite compounds. 8 refs.