title: Evidence of the pressure-induced conductivity switching of yttrium-doped SrTiO3.
abstract: The electrical transport properties of undoped and yttrium-doped strontium titanate (Sr(Ti1 - x Y x )O3 - δ , x  =  0, 0.02) under high pressure were investigated with in situ impedance spectroscopy measurements. A pressure-induced conductivity switching for undoped and 2 mole% Y-doped strontium titanate is observed at around ~10.0 and 7.0 GPa respectively, which are caused by a cubic to tetragonal I4/mcm phase transition. The decrease of the phase transition point of 2 mole% Y-doped strontium titanate can be attributed to larger Y(3+) atoms occupying the B-site and the creation of more oxygen vacancies, which lead to octahedra tilting and symmetry breaking. The results of the voltage-bias dependence of grain-boundary impedance of undoped and 2 mole% Y-doped strontium titanate at different pressures revealed that Schottky-type potential barriers formed at grain boundaries are the key factor for the accumulation of oxygen vacancy at the interface under pressure.
authors.affiliation: Key Laboratory of High-Temperature and High-Pressure Study of the Earth's Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, Guizhou 550081, People's Republic of China.
authors.forename: LiDong
authors.initials: L
authors.lastname: Dai
authors.forename: Lei
authors.initials: L
authors.lastname: Wu
authors.forename: HePing
authors.initials: H
authors.lastname: Li
authors.forename: HaiYing
authors.initials: H
authors.lastname: Hu
authors.forename: YuKai
authors.initials: Y
authors.lastname: Zhuang
authors.forename: KaiXiang
authors.initials: K
authors.lastname: Liu