Magnetic phase transition in PdxCoyO2

The nonstoichiometric compound PdxCoyO2 (x=0.72,y=0.68) were carefully prepared by the metathetical reaction and characterized by the measurements of the powder X-ray diffraction, the inductively coupled plasma spectrum, the DC magnetic susceptibility, and the specific heat. The stoichiometric PdCoO2 exhibits Pauli-paramagnetism, while two magnetic phase transitions were indeed observed in Pd0.72Co0.68O2. The deviation of field-cooled from zero-field-cooled curves appears below 55 K, indicating a certain kind of antiferromagnetic phase transition. The well-defined cusp is seen with a peak at Tg=4.5 K, indicating the existence of spin-glass like transition