Semiconductor-metal transition in novel Cd2Os2O7

Abstract Cd 2 Os 2 O 7 has been prepared for the first time and has the pyrochlore structure with a cubic cell edge of 10.17 A at room temperature. Electrical, magnetic, and DSC measurements on single crystals of this compound show a sharp transition at 225 K which we interpret to be an electronic, second-order, metal-semiconductor transition. The low-temperature semiconducting phase is probably antiferromagnetic.