Effects of corner-sharing of TiO_6 octahedra on carrier transport in Ti-containing n-type oxide semiconductor

摘要

We measured carrier transport properties of TiO_2 bulk single-crystals along the directions parallel to edge-shared and corner-shared octahedra. Carrier concentration and effective mass were similar for both directions, while carrier relaxation time for edge-shared TiO_6, octahedra was approx 3 times as large as that for comer-shared TiO_6 octahedra. This finding suggests that Ti-containing oxides with edge-shared TiO_6 octahedra would be better candidates for thermoelectric materials than those with comer-shared octahedra.