Structural anomalies, spin transitions and charge disproportionation in LnCoO3

Abstract

The diamagnetic-paramagnetic and insulator-metal transitions in LnCoO3 perovskites (Ln = La, Y, rare earths) are reinterpreted and modeled as a two-level excitation process. In distinction to previous models, the present approach can be characterized as a LS-HS-IS (low-high-intermediate spin) scenario. The first level is the local excitation of HS Co3+ species in the LS ground state. The second excitation is based on the interatomic electron transfer between the LS/HS pairs, leading finally to a stabilization of the metallic phase based on IS Co3+. The model parameters have been quantified for Ln = La, Pr and Nd samples using the powder neutron diffraction on the thermal expansion of Co-O bonds, that is associated with the two successive spin transitions. The same model is applied to interpret the magnetic susceptibility of LaCoO3 and YCoO3.

52.Conference on Magnetism and Magnetic Materials, November 2007, Tampa

References in corpus (7)

• The spin state transition in LaCoO${}_3$; revising a revision
• Structural phenomena associated with the spin-state transition in LaCoO3
• Evidence for a Low-Spin to Intermediate-Spin State Transition in LaCoO3
• Spin-state transition in LaCoO3: direct neutron spectroscopic evidence of excited magnetic states
• Pressure-Induced Intermediate-to-Low Spin State Transition in LaCoO3
• Structural anomalies associated with the electronic and spin transitions in LnCoO3
• Spin-State Transition and Metal-Insulator Transition in La${}_{1-x}$Eu${}_x$CoO${}_3$}

Cited by in corpus (3)

• Properties of the hole and electron doped perovskites LnCoO3
• Stabilization of the high-spin state of Co${}^{3+}$ in LaCo${}_{1-x}$Rh${}_x$O${}_3$
• Cobalt spin state above the valence and spin-state transition in (Pr0.7Sm0.3)0.7Ca0.3CoO3