高压合成新型铜基稀土钙钛矿RCuO3 (R = 稀土)：压力对晶格及电子结构的调控

A great deal of interest has been focused on the strongly correlated system of rare earth-3d transition metal perovskites RMO3（R = rare earth，M = 3d transition metal）. In this system, there is a rich variety of intriguing phenomena such as multiferroicity, high-temperature superconductivity and colossal magnetoresistance due to the strong correlations among lattice dynamics, charges, spins and orbitals. However, very little information has been known for RCuO3 with an unusual high valence state of Cu3+ because it is the most difficult to synthesize under ambient pressure. In this project, we propose to synthesize a series of new Cu-based rare earth perovskites RCuO3 (R=Ce，Pr，Nd，Sm……) under high pressures and study their structural and physical properties by fully comprehensive measurements under both ambient and high-pressure conditions. A side-by-side comparison between RCuO3 and other rare earth-3d transition metal perovskites would allow us to reveal the effects of high pressure on the crystal and electronic structures, and therefore provide a roadmap for developing new quantum functional materials.

以稀土-3d过渡金属钙钛矿RMO3（R=稀土，M=3d过渡金属）为代表的强关联电子体系一直是凝聚态物理研究的前沿焦点。在这些体系中，晶格、电荷、自旋和轨道等多个自由度之间的相互耦合和竞争会诱导出多铁性、高温超导、庞磁阻效应等奇异的物理现象。然而，具有反常高价态Cu3+的铜基稀土过渡金属钙钛矿RCuO3由于很难通过常压手段制备而一直没有得到系统研究。本项目计划利用极端高压条件合成一系列新型铜基稀土钙钛矿RCuO3（R=Ce，Pr，Nd，Sm……），结合常压和高压表征技术，系统研究它们的结构和物性演化规律，将现有的稀土-3d过渡金属钙钛矿拓展到铜基体系，并通过与其它相应的Ti，V，……Ni基体系进行详细对比，揭示压力对晶格及电子结构的调控作用，从而为探索新型量子功能材料提供更加详实的实验依据。

稀土-3d 过渡金属钙钛矿 RMO3（R = 稀土，M = 3d 过渡金属）因其晶格、电荷、自旋和轨道之间的强关联性而备受关注。压力作为基本的热力学参数之一，会影响晶体结构，并且能够调控磁性和输运特性。在本项目中，我们在高压下合成了一系列新型铜基稀土钙钛矿 RCuO3（R=Ce、Pr、Nd、Sm、Eu……），并系统研究了它们的局域结构以及输运和磁性等物理特性，有助于更好地理解晶体结构和物性之间的密切关系。