High-Pressure Synthesis of Non-Stoichiometric Li _x WO₃ (0.5 ≤ x ≤ 1.0) with LiNbO₃ Structure

Compounds with the LiNbO₃-type structure are important for a variety of applications, such as piezoelectric sensors, while recent attention has been paid to magnetic and electronic properties. However, all the materials reported are stoichiometric. This work reports on the high-pressure synthesis of lithium tungsten bronze Li _x WO₃ with the LiNbO₃-type structure, with a substantial non-stoichiometry (0.5 ≤ x ≤ 1). Li_0.8WO₃ exhibit a metallic conductivity. This phase is related to an ambient-pressure perovskite phase (0 ≤ x ≤ 0.5) by the octahedral tilting switching between a^-a^-a^- and a⁺a⁺a⁺.