Abstract
Abstract In this article, we studied on metal-insulator transition with oxygen content parameter d in the Sm2-xCexCuO4+d systems. We studied the d-wave pairing symmetry for the Sm2-xCexCuO4+d systems further. In the Sm2-xCexCuO4+d systems, the antiferromagnetic order of Sm3+ is 6.0 K for x = 0, and 4.6 K for x=0.15 in 1 kG applied magnetic field. After oxygen-reduced the as-sintered Sm1.85Ce0.15CuO4+d sample change to superconductor with Tc = 24 K. The crystal structure, magnetism, specific heat, and electric property were discussed in this system. A superconductor-insulator transition around d = 0.05 was observed. In order to confirm the pairing state of the high Tc electron doped superconductor Sm1.85Ce0.15CuO4+d was chosen for further study. We use a c-axis alignment power method and particle distribution to calculate the penetration depth function of temperature lab(T) for vertical CuO2 planes of applied field. The temperature dependence of penetration depth change shows a linear power law component. The linear term show that wave equation was d-wave symmetry, but our data with larger T2 term show the inhomogenous oxygen content, disorder-scatter dirty d-wave-like T2 law.