Transport and magnetic properties of delafossite CuAl1-xMnxO2 ceramics

We report on the transport and magnetic properties of Mn-doped CuAlO2 ceramics (CuAl1-xMnxO2, 0 less than or equal to x less than or equal to 0.05) fabricated by standard solid solution method in an air atmosphere at a sintering temperature of 1150 degreesC. The equilibrium solubility of Mn ions in CuAlO2 was found to be as low as 3 mol%. Non-doped CuAlO2 ceramics were semiconducting with a hole concentration of similar to5.8 x 10(16) cm(-3) and an increase of Mn ion rapidly reduced the hole concentration. The magnetization measurements for all CuAl1-xMnxO2 samples showed paramagnetic behaviors and a negative value of the Curie-Weiss temperature corresponding to antiferromagnetic exchange coupling between Mn ions in delafossite CuAlO2 lattice. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.