Preparation and physical properties of CuAl_(1-x)Mn_xO_2 (0 < = x < = 0.2) delafossites

摘要

The formation of a CuAl_(1-x)Mn_xO_2 solid solution for a limited range of x values (0 < = x < = 0.2) is demonstrated. The samples were synthesized by solid state reactions in silica sealed tubes. They crystallize with the 3R delafossite structure (space group R3-bar m). Magnetic studies show that Mn~(3+) ions are in the HS state and that the predominant interactions are antiferromagnetic. The oxides are semiconductors with an activation energy decreasing with x.