Evolution of Structural, Electronic and Magneto-transport Properties of Sr2Ir_(1-x)Ti_xO_4 5d Based Oxide

摘要

To investigate the effect of chemical doping on structural and transport properties in Sr_2lrO_4, in this study we have doped Ti~(4+) (3d~0) at Ir~(4+) (5d~5) site. Thus Ti doping introduces hole in the electronic band moreover, it also weaken the spin orbital coupling (SOC) and enhance electronic correlation (U). We have prepared the polycrystalline samples of Sr_2Ir_1-xTixO_4 with x= 0.0 0.05 and 0.10 with solid state reaction method. Single phase and chemically pure samples were obtained. All samples crystalizes in tetragonal structure and I_(41)/acd symmetry. The structural analysis shows the evolution oflattice parameter with doping. The temperature dependent resistivity is measured using four probe technique down in the temperature range 5 K -300 K. The resistivity increases with Ti doping. Temperature dependency of resistivity is explained by thermal activated 2-dimensional Mott Variable Hopping range model. To further understand the transport behavior both temperature and field dependent magneto-resistance is also studied. Negative magneto-resistance (MR) has been observed for all samples at 50 K. The MR shows quadratic field dependence at high field, implies a relevance of a quantum interference effect in this spin orbital coupled insulator.