Transcript PPTX
Class 08. LnNiO3 LaNiO3 and LaCuO3 are some of the few (undoped) metals. Materials 286K [email protected] Class 08. LnNiO3 Strong lattice effects in the M–I transition of LnNiO3 Torrance, Lacorre, Nazzal, Ansaldo, Niedermayer, Phys. Rev. B. 45 (1992) 8209–8212. Materials 286K [email protected] Class 08. LnNiO3 The transition is nicely tunable with average rare-earth size Medarde et al., J. Phys. Condensed Matter 9 (1997) 1679. Materials 286K [email protected] Class 08. LnNiO3 Pressure effects --- high pressures are like large A-cations Obradors et al. Phys. Rev. B 47 (1993) 12353. Materials 286K [email protected] Class 08. LnNiO3 Lattice dynamics is important: Strong isotope effect Medarde, Lacorre, Conder, Fauth, Furrer, Phys. Rev. Lett. 80 (1998) 2397–2400. Materials 286K [email protected] Class 08. LnNiO3 The room-temperature crystal structures Medarde et al., J. Phys. Condensed Matter 9 (1997) 1679. Materials 286K [email protected] Class 08. LnNiO3 Perovskite structures: Group-subgroup relations from James Rondinelli, Northwestern. Materials 286K [email protected] Class 08. LnNiO3 The complete phase diagram orthorhombic monoclinic from James Rondinelli, Northwestern. Materials 286K [email protected] Class 08. LnNiO3 Monoclinic phase from James Rondinelli, Northwestern. Materials 286K [email protected] Class 08. LnNiO3 Decomposing the monoclinic structure into into its irreducible representations: = from James Rondinelli, Northwestern. Materials 286K [email protected] Class 08. LnNiO3 TMI – metal-insulator transition correlates with rotations, breathing & bending of octahedra, while TN – AFM ordering transition correlates with first-order Jahn-Teller type of distortions Breathing distortion correlates with MIT Jahn-Teller distortion correlates with magnetism Balachandran, Rondinelli, Phys. Rev. B 88 (2013) 054101. Materials 286K [email protected] 11 Class 08. LnCoO3 First-order localized to delocalized transition in LaCoO3 Raccah, Goodenough, Phys. Rev. 155 (1967) 932–943. Materials 286K [email protected] 12 Class 08. LnCoO3 First-order localized to delocalized transition in LaCoO3 Raccah, Goodenough, Phys. Rev. 155 (1967) 932–943. Materials 286K [email protected] 13 Class 08. LnCoO3 First-order localized to delocalized transition in LaCoO3 Raccah, Goodenough, Phys. Rev. 155 (1967) 932–943. Materials 286K [email protected] 14 Class 08. LnCoO3 More subtle structural effects (orbital ordering?): Maris, Ren, Volotchaev, Lorenz, Palstra, Phys. Rev. B. 67 (2003) 224423(1–5). Materials 286K [email protected] 15 Class 08. LnCoO3 M–I transition with temperature and hole doping (Sr substitution) Bhide, Rajoria, Rao, Rama Rao, Jadhao, Phys. Rev. B. 12 (1975) 2832–2843. Materials 286K [email protected] 16 Class 08. LnCoO3 La0.5Sr0.5CoO3–d prepared under different annealing conditions Haggerty, Seshadri, J. Phys. Condensed Matter 16 (2004) 6477–6484. Materials 286K [email protected] 17 Class 08. LnCoO3 La0.5Sr0.5CoO3–d prepared under different annealing conditions Haggerty, Seshadri, J. Phys. Condensed Matter 16 (2004) 6477–6484. Materials 286K [email protected] 18 Class 08. LnCoO3 La0.5Sr0.5CoO3 band structure. Majority and minority bands have very different bandwidths. Haggerty, Seshadri, J. Phys. Condensed Matter 16 (2004) 6477–6484. Materials 286K [email protected] 19