First principles study of the spin state transitions in GdBaCo${}_2$O${}_{5.5}$

Abstract

Electronic structure calculations were carried out on the compound GdBaCo${}_2$O${}_{5.5}$. The electronic structure variation with a change in the spin state of the Co${}^{3+}$ ion in an octahedral environment has been studied. All the insulating phases are described and possible scenarios for the metallic ones are presented. Orbital ordering is shown to take place and the electronic structure leading to it is determined. The Ising-like anisotropy shown experimentally can be predicted. Also, big unquenched orbital angular momenta are calculated and their origin is described.

arXiv commentCorrections after refereeing included; 7 pages, 7 figures

References in corpus (7)

• Correlated metals and the LDA+U method
• Transport and magnetic properties of GdBaCo_{2}O_{5+x} single crystals: A cobalt oxide with square-lattice CoO_2 planes over a wide range of electron and hole doping
• Selective Spin-State Switch and Metal-Insulator Transition in \boldmath $\mathrm{GdBaC}{\mathrm{o}}_2{\mathrm{O}}_{5.5}$
• A different look at the spin state of Co${}^{3+}$ ions in CoO${}_5$ pyramidal coordination
• Ising-like Spin Anisotropy and Competing Antiferromagnetic - Ferromagnetic Orders in GdBaCo_{2}O_{5.5} Single Crystals
• Electron-Hole Asymmetry in GdBaCo_{2}O_{5+x}: Evidence for Spin Blockade of Electron Transport in a Correlated Electron System
• Spin state and phase competition in TbBaCo_{2}O_{5.5} and the lanthanide series LnBaCo_{2}O_{5+δ} (0<=δ<=1)

Cited by in corpus (3)

• Microscopic Evidence of Spin State Order and Spin State Phase Separation in Layered Cobaltites RBaCo2O5.5 with R=Y, Tb, Dy, and Ho
• Probing phase coexistence and stabilization of the spin-ordered ferrimagnetic state by Calcium addition in the YBa_{1-x}Ca_{x}Co_{2}O_{5.5} layered cobaltites using neutron diffraction
• Coupling of magnetism and transport properties to the lattice degrees of freedom in NdBaCo${}_2$O${}_{5+\delta }$ ($\delta \sim 0.65$)