Magnetic and Electric Properties of Sr2-xYxCoO4, (0.50 <= x <= 0.80) Layered Perovskites

Abstract

The electric and magnetic properties of Sr2-xYxCoO4 layered perovskites have been investigated systematically over the doping range 0.50 <= x <= 0.80. It was found that both Sr1.5Y0.5CoO4 and Sr1.4Y0.6CoO4 undergo ferromagnetic (FM) transition around 145 K and 120 K, respectively. On the other hand, Sr1.3Y0.7CoO4 and Sr1.2Y0.8CoO4 compounds showed paramagnetic behavior over a wide range of temperatures. In addition, spin-glass transition (T-SG) was observed at 10 K for Sr1.3Y0.7CoO4. All investigated samples are semiconducting-like within the temperature range of 10-300 K. The temperature dependence of the electrical resistivity, rho(T), was described by two-dimensional variable range hopping (2D-VRH) model at 50 K < T <= 300 K. Comparison with other layered perovskites was discussed in this work.