Structural, magnetic and electric properties of Delafossite-type oxide, Cu1-xAgxCrO2 (0 < x < 0.5)

Polycrystalline samples of the delafossite Cr oxide Cu1-xAgxCrO2 were investigated to clarify its transport properties. The synthetized phases are found to contain a slight oxygen excess (δ = 0.06). The valence state of the Cr ions in the Cu1-xAgxCrO2 samples was identified as >3+ by analysing their TGA spectra, their lattice parameters and their electrical properties. The temperature dependence of zerofield-cooling magnetization was measured. All samples exhibits paramagnetic behaviour at high temperature. At low temperature they exhibit a clear ferromagnetic (FM) transition around 130 K. For x = 0.10 the samples exhibit an AFM transition at 25K. Clear hysteresis loops indicate that FM order exists in the Ag-doped samples at 2 K. All samples behave like semiconductors.