Materials 286K [email protected] Class 08. LnNiO 3 LaNiO 3 and LaCuO 3 are some of the few (undoped) metals.

Materials 286K [email protected]

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]

The transition is nicely tunable with average rare-earth size

Class 08. LnNiO3

Medarde et al., J. Phys. Condensed Matter 9 (1997) 1679.

Materials 286K [email protected]

Obradors et al. Phys. Rev. B 47 (1993) 12353.

Pressure effects --- high pressures are like large A-cations

Class 08. LnNiO3

Materials 286K [email protected]

Medarde, Lacorre, Conder, Fauth, Furrer, Phys. Rev. Lett. 80 (1998) 2397–2400.

Lattice dynamics is important: Strong isotope effect

Class 08. LnNiO3

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]

Perovskite structures: Group-subgroup relations

Class 08. LnNiO3

from James Rondinelli, Northwestern.

Materials 286K [email protected]

The complete phase diagram

orthorhombic

monoclinic

Class 08. LnNiO3

from James Rondinelli, Northwestern.

Materials 286K [email protected]

Monoclinic phase

Class 08. LnNiO3

from James Rondinelli, Northwestern.

Materials 286K [email protected]

Decomposing the monoclinic structure into into its irreducible representations:

=

Class 08. LnNiO3

from James Rondinelli, Northwestern.

Materials 286K [email protected] 11

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.

Class 08. LnNiO3

Materials 286K [email protected] 12

First-order localized to delocalized transition in LaCoO3

Raccah, Goodenough, Phys. Rev. 155 (1967) 932–943.

Class 08. LnCoO3

Materials 286K [email protected] 13

First-order localized to delocalized transition in LaCoO3

Raccah, Goodenough, Phys. Rev. 155 (1967) 932–943.

Class 08. LnCoO3

Materials 286K [email protected] 14

First-order localized to delocalized transition in LaCoO3

Raccah, Goodenough, Phys. Rev. 155 (1967) 932–943.

Class 08. LnCoO3

Materials 286K [email protected] 15

More subtle structural effects (orbital ordering?):

Maris, Ren, Volotchaev, Lorenz, Palstra, Phys. Rev. B. 67 (2003) 224423(1–5).

Class 08. LnCoO3

Materials 286K [email protected] 16

M–I transition with temperature and hole doping (Sr substitution)

Bhide, Rajoria, Rao, Rama Rao, Jadhao, Phys. Rev. B. 12 (1975) 2832–2843.

Class 08. LnCoO3

Materials 286K [email protected] 17

La0.5Sr0.5CoO3–d prepared under different annealing conditions

Haggerty, Seshadri, J. Phys. Condensed Matter 16 (2004) 6477–6484.

Class 08. LnCoO3

Materials 286K [email protected] 18

Haggerty, Seshadri, J. Phys. Condensed Matter 16 (2004) 6477–6484.

Class 08. LnCoO3

La0.5Sr0.5CoO3–d prepared under different annealing conditions

Materials 286K [email protected] 19

La0.5Sr0.5CoO3 band structure. Majority and minority bands have very different bandwidths.

Haggerty, Seshadri, J. Phys. Condensed Matter 16 (2004) 6477–6484.

Class 08. LnCoO3