Y掺杂BaZrO3 质子导体的常压和高压合成及表征

利用固相反应法和高压高温法研究BaZr_1-xYxO₃(x=0,0.05,0.10,0.15,0.20)的合成. XRD和Raman谱结果表明, 在常压和1 300 ℃进行固相反应不能得到纯立方钙钛矿相BaZr_1-xYxO₃. 对上述样品进行高压（3.6 GPa）再处理, 低掺杂量样品（x=0,0.05）在500 ℃时得到较纯的立方钙钛矿相, 表明增加压力可促进固相反应; 在高掺杂量样品（x≥0.1）中出现少量BaCO₃和m-ZrO₂相, 表明增加压力不利于固相反应. 高压合成样品的晶格常数和晶胞体积均小于常压合成的样品. 保持压力不变, 当温度为1 000 ℃时, 各样品均出现明显的BaO杂相. 表明在500 ℃时, 高压处理可提高BaZr_1-xYxO₃

Synthesis and Characterization of Y Doped BaZrO3 Protonic Conductors under Common and High Pressure

Samples BaZr_1-xYxO₃(x=0,0.05,0.10,0.15,0.20) were prepared by solid-state reaction method under high-pressure and high-temperature. XRD and Raman measurements show that the products obtained by solid state reaction method at 1 300 ℃ belonged to cubic perovskite structure, but part of high degree diffract peaks split slightly. The samples （x=0,0.05） were in pure cubic perovskite structure under high pressure (3.6 GPa) and temperature (500 ℃), which shows that press can accelerate the reaction. But some BaCO₃ and m-ZrO₂ appeared in other samples （x≥0.1）, which shows that press baffled the reaction. Under 3.6 GPa at1 000 ℃, the peaks of BaO appeared clearly and increased with the content of Y³⁺. Therefore, to synthesis cubic perovskite structure BaZr_1-xYxO₃ under high-pressure and high-temperature, the temperature should be below 500 ℃.