“…Various high-and low-temperature measurements including conductivity (1)(2)(3)(4)(5)(6), weight change (7,8), thermoelectric power (3,4), diffusion (9)(10)(11), transient conductivity (12)(13)(14), Hall effect (15)(16)(17)(18)(19)(20), and dielectric measurements (21)(22)(23)(24)(25)(26) have been made for the purpose of elucidating its defect structure and physical properties. Various high-and low-temperature measurements including conductivity (1)(2)(3)(4)(5)(6), weight change (7,8), thermoelectric power (3,4), diffusion (9)(10)(11), transient conductivity (12)(13)(14), Hall effect (15)(16)(17)(18)…”