Anomalous perovskite PbRuO3 stabilized under high pressure

• Autores: Cheng, J. G.; Kweon, K. E.; Zhou, J. S.; Alonso, J. A.; Kong, P. P.; Liu, Y.; Jin,Changqing; Wu, Junjie; Lin, Jung Fu; Larregola, Sebastian Alberto; Yang, Wenge; Shen, Guoyin; MacDonald, A. H.; Manthiram, Arumugam; Hwang, G. S.; Goodenough, John B.
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: PEROVSKITE; HIGH PRESSURE; INTERMETALLIC; RUTHENATE
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Perovskite oxides ABO3 are important materials used as components in electronic devices. The highly compact crystal structure consists of a framework of corner-shared BO6 octahedra enclosing the A-site cations. Because of these structural features, forming a strong bond between A and B cations is highly unlikely and has not been reported in the literature. Here we report a pressure-induced first-order transition in PbRuO3 from a common orthorhombic phase (Pbnm) to an orthorhombic phase (Pbn21) at 32 GPa by using synchrotron X-ray diffraction. This transition has been further verified with resistivity measurements and Raman spectra under high pressure. In contrast to most well-studied perovskites under high pressure, the Pbn21 phase of PbRuO3 stabilized at high pressure is a polar perovskite. More interestingly, the Pbn21 phase has the most distorted octahedra and a shortest Pb—Ru bond length relative to the average Pb—Ru bond length that has ever been reported in a perovskite structure. We have also simulated the behavior of the PbRuO3 perovskite under high pressure by first principles calculations. The calculated critical pressure for the phase transition and evolution of lattice parameters under pressure match the experimental results quantitatively. Our calculations also reveal that the hybridization between a Ru:t2g orbital and an sp hybrid on Pb increases dramatically in the Pbnm phase under pressure. This pressure-induced change destabilizes the Pbnm phase to give a phase transition to the Pbn21 phase where electrons in the overlapping orbitals form bonding and antibonding states along the shortest Ru—Pb direction at P > Pc.
Fil: Cheng, J. G.. University of Texas at Austin; Estados Unidos. Chinese Academy of Sciences; República de China
Fil: Kweon, K. E.. University of Texas at Austin; Estados Unidos
Fil: Zhou, J. S.. University of Texas at Austin; Estados Unidos
Fil: Alonso, J. A.. Instituto de Ciencia de Materiales de Madrid; España
Fil: Kong, P. P.. Chinese Academy of Sciences; República de China
Fil: Liu, Y.. Chinese Academy of Sciences; República de China
Fil: Jin,Changqing. Chinese Academy of Sciences; República de China
Fil: Wu, Junjie. Chinese Academy of Sciences; República de China. University of Texas at Austin; Estados Unidos
Fil: Lin, Jung Fu. University of Texas at Austin; Estados Unidos
Fil: Larregola, Sebastian Alberto. University of Texas at Austin; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; Argentina
Fil: Yang, Wenge. Carnegie Institution of Washington; Estados Unidos
Fil: Shen, Guoyin. Carnegie Institution of Washington; Estados Unidos
Fil: MacDonald, A. H.. University of Texas at Austin; Estados Unidos
Fil: Manthiram, Arumugam. University of Texas at Austin; Estados Unidos
Fil: Hwang, G. S.. University of Texas at Austin; Estados Unidos
Fil: Goodenough, John B.. University of Texas at Austin; Estados Unidos