HIGH-PRESSURE SYNTHESIS AND PHYSICAL PROPERTIES OF NbSr_2 (Dy_(1.5)Ce_(0.5))Cu_2O_(10)

摘要

In the present study, we have successfully synthesized and structurally characterized a new 1222-type Dy-based niobio-cuprate for the first time with the chemical formula, NbSr_2(Dy_(1.5)Ce_(0.5))Cu_2O_(10) by high-pressure and elevated temperature technique under different synthesis conditions. A good quality polycrystalline ceramic sample was pre_pared at 1723 K and 6 GPa for 2 h. The title compound crystallizes in a tetragonal symmetry of space group I4/mmm with lattice parameters a = b = 3.864(5) _ and c = 28.68(4) _. The temperature dependence of (low field) magnetic susceptibilities reveals mixed magnetic state at __26 K. The shape of the M(H) curve measured at 1.8 K data suggests canted antiferromagnetic interaction in this title compound. The temperature dependence of electrical resistivity shows semiconducting behavior and a relatively large negative magnetoresistance 4%) appears around 200 K. A detailed study on the synthesis, structural, magnetic and transport properties is presented in this article.