Scholarlink

<p>We report the experimental verification of a strain-induced symmetry change associated with octahedral geometry in epitaxial CaRuO<sub>3</sub> thin films, where the decoupling of octahedral rotation modes dictates both macroscopic elastic and quantum transport properties. High-resolution X-ray diffraction reveals that a 1.43% epitaxial tensile strain from SrTiO<sub>3</sub> (0 0 1) substrates triggers a structural transition from the bulk orthorhombic (<i>Pbnm</i>) to a tetragonal (<i>P</i>4/<i>mbm</i>) phase. This symmetry transition induces a <i>a</i><sup>0</sup><i>a</i><sup>0</sup><i>c</i><sup>+</sup> rotation angle crossover characterized by the linearization of apical Ru–O–Ru bond angles to 180<b>°</b>, and a simultaneous equatorial buckling to 137.5<b>°</b>. Such RuO<sub>6</sub> reconfiguration leads to significant mechanical hardening along the apical axis, manifested by an anomalous effective Poisson ratio (ν<sub>eff</sub>) of 0.13. Furthermore, the anisotropic octahedral distortion, driven by the equatorial buckling and bond elongation (2.095&#xa0;Å), enhanced electronic correlations, thereby increasing the effective mass and stabilizing a non-Fermi liquid state with a linear temperature dependence of resistivity. By quantifying these structural reconfigurations and their subsequent impact on elastic and electronic functionalities, our findings provide a robust framework for the rational design of ruthenate-based oxide electronics.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Strain-induced symmetry transition and non-Fermi liquid behavior in CaRuO3 thin films

  • 期刊论文

  • 发表日期：

    2026年3月12日

查看全文
  • Sang-A Lee,
  • Jae-Yeol Hwang

摘要

We report the experimental verification of a strain-induced symmetry change associated with octahedral geometry in epitaxial CaRuO3 thin films, where the decoupling of octahedral rotation modes dictates both macroscopic elastic and quantum transport properties. High-resolution X-ray diffraction reveals that a 1.43% epitaxial tensile strain from SrTiO3 (0 0 1) substrates triggers a structural transition from the bulk orthorhombic (Pbnm) to a tetragonal (P4/mbm) phase. This symmetry transition induces a a0a0c+ rotation angle crossover characterized by the linearization of apical Ru–O–Ru bond angles to 180°, and a simultaneous equatorial buckling to 137.5°. Such RuO6 reconfiguration leads to significant mechanical hardening along the apical axis, manifested by an anomalous effective Poisson ratio (νeff) of 0.13. Furthermore, the anisotropic octahedral distortion, driven by the equatorial buckling and bond elongation (2.095 Å), enhanced electronic correlations, thereby increasing the effective mass and stabilizing a non-Fermi liquid state with a linear temperature dependence of resistivity. By quantifying these structural reconfigurations and their subsequent impact on elastic and electronic functionalities, our findings provide a robust framework for the rational design of ruthenate-based oxide electronics.