Local crystal structure and physical properties change of $\mathrm{p}$-type transparent conducting oxide: $\mathrm{CuCrO_{2}}$ upon Ti-substitution

Combination of high optical transparency and good electrical conductivity is realized in CuCrO$_2$, a $p$-type transparent conducting oxide. With an aim to better its physical properties, CuCr$_{1-x}$Ti$_{x}$O$_{2}$ ($x$ = 0, 0.05, 0.1) series was prepared and investigated for its structural, electrical transport and optical properties. Along with lattice parameter values, refinement of X-ray diffraction profiles confirms the solubility limit of Ti within the delafossite unit cell. Electrical resistivity and heat capacity measured by varying the temperature, further characterize the Ti-substituted compositions. As determined from the ultraviolet-visible (UV-Vis) spectroscopy, no significant change takes place in the optical gap of CuCrO$_2$ with Ti addition. Apart from confirming the $4+$ valence state of Ti, X-ray absorption near edge structure highlight the subtle changes taking place in the Cu$-$O hybridization upon Ti - substitution. Analysis of temperature dependent extended X-ray absorption fine structure (EXAFS) spectroscopy recorded at the Cr and Cu K-edge emphasizes the impact of redistribution of charges on the local crystal structure. Cu$-$Cu hybridization along $a$-axis appears to be influenced mainly by the temperature and only slightly by Ti substitution.