标题： 铁电 Hf0.5Zr0.5O2 薄膜中极化与氧空位迁移的耦合使得在室温以上实现了电控热存储器 显示英文标题

标题： The coupling of polarization and oxygen vacancy migration in ferroelectric Hf0.5Zr0.5O2 thin films enables electrically controlled thermal memories above room temperature

摘要： 我们研究了外延Hf0.5Zr0.5O2铁电薄膜作为非易失性电场调制热存储器的潜在候选材料。 金属/Hf0.5Zr0.5O2/YSZ器件的热导率对电场的依赖性表现出迟滞特性，类似于极化与电场的迟滞回线，在顶部金属电极施加大正（负）电压时达到最大（最小）。 这种动态热响应与铁电极化和氧离子迁移之间的耦合相容，在此过程中氧空位是主要的声子散射源，极化作为电活性离子迁移障碍物，产生了迟滞效应。 这种新机制实现了两种非易失性热状态：高（ON）和低（OFF）热导率，ON/OFF比为1.6。 ON和OFF状态均表现出良好的时间稳定性，尽管开关速度受到YSZ电极中离子迁移率的限制。 显示英文摘要

摘要： Here we investigate epitaxial Hf0.5Zr0.5O2 ferroelectric thin films as potential candidates to be used as non-volatile electric-field-modulated thermal memories. The electric-field dependence of the thermal conductivity of metal/Hf0.5Zr0.5O2/YSZ devices is found to be hysteretic, resembling the polarization vs electric field hysteresis loops, being maximum (minimum) at large applied positive (negative) voltages from the top metallic electrode. This dynamic thermal response is compatible with the coupling between the ferroelectric polarization and the oxygen ion migration, in which the oxygen vacancies are the main phonon scattering sources and the polarization acts as an electrically active ion migration barrier that creates the hysteresis. This new mechanism enables two non-volatile thermal states: high (ON) and low (OFF) thermal conductivity, with an ON/OFF ratio of 1.6. Both the ON and OFF states exhibit high stability over time, though the switching speed is limited by ion mobility in the YSZ electrode.