Strong Electron Hybridization and Fermi-to-Non-Fermi Liquid Transition in LaCu3Ir4O12

详细信息    查看全文

• 作者：Man-Rong Li ; Maria Retuerto ; Zheng Deng ; Tapati Sarkar ; Javier S谩nchez-Ben铆tez ; Mark C. Croft ; Tanusri Saha Dasgupta ; Tilak Das ; Trevor A. Tyson ; David Walker ; Martha Greenblatt
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：January 13, 2015
• 年：2015
• 卷：27
• 期：1
• 页码：211-217
• 全文大小：473K
• ISSN：1520-5002

文摘

The AA鈥?sub>3B₄O₁₂-type quadruple perovskite LaCu₃Ir₄O₁₂ prepared at high pressure (9 GPa) and temperature (1523 K) crystallizes in cubic symmetry (Im3虆, a = 7.52418(3) 脜) with square planar CuO₄ and octahedral IrO₆ coordination as established from synchrotron powder X-ray diffraction studies. Both crystal structure and X-ray absorption near edge spectroscopy analyses indicate formal oxidation states of LaCu²⁺₃Ir^3.75+₄O₁₂. The temperature dependence of resistivity of LaCu₃Ir₄O₁₂ is metallic down to 10 K, with Femi-liquid behavior above T* 鈭?155 K, and non-Fermi-liquid behavior below T*. The two-fluid behavior of magnetic susceptibility and the dramatic downturn of the resistivity below T* indicate strong Cu²⁺ 3d and Ir^3.75+ 5d orbital hybridization below T*, also supported by an enhanced electronic specific heat coefficient at low temperature. Theoretical calculations are in good agreement with the experimental results and show that the electronic structure of LaCu₃Ir₄O₁₂ is different from that of CaCu²⁺₃Ir⁴⁺₄O₁₂, which is also metallic down to 0.5 K, but presents non-Fermi liquid behavior above T* 鈭?80 K and strong Cu-3d鈥揑r-5d orbital coupling at significantly lower temperature (T < T* 鈭?80 K).