Petkov V, Rao T Durga, Zafar A, Abeykoon A M Milinda, Fletcher E, Peng J, Mao Z Q, Ke X
Department of Physics, Central Michigan University, Mt. Pleasant, MI 48858, United States of America.
Department of Physics, GITAM, Visakhapatnam, Andhra Pradesh 530045, India.
J Phys Condens Matter. 2022 Nov 8;51(1). doi: 10.1088/1361-648X/ac9dda.
We report pair distribution function studies on the relationship between the metal-insulator transition (MIT) and lattice distortions in pure and Ti-substituted bilayer CaRuO. Structural refinements performed as a function of temperature, magnetic field and length scale reveal the presence of lattice distortions not only within but also orthogonal to the bilayers. Because of the distortions, the local and average crystal structure differ across a broad temperature region extending from room temperature to temperatures below the MIT. The coexistence of distinct lattice distortions is likely to be behind the marked structural flexibility of CaRuOunder external stimuli. This observation highlights the ubiquity of lattice distortions in an archetypal Mott system and calls for similar studies on other families of strongly correlated materials.
我们报告了关于纯的和钛取代的双层钙钌氧化物中金属-绝缘体转变（MIT）与晶格畸变之间关系的对分布函数研究。作为温度、磁场和长度尺度的函数进行的结构精修表明，不仅在双层内部而且在与双层正交的方向上都存在晶格畸变。由于这些畸变，从室温到低于MIT的温度范围内的很宽温度区域内，局部和平均晶体结构都有所不同。不同晶格畸变的共存可能是钙钌氧化物在外部刺激下具有显著结构灵活性的原因。这一观察结果突出了典型莫特系统中晶格畸变的普遍性，并呼吁对其他强关联材料家族进行类似研究。
