Article

# Mott Transition and Suppression of Orbital Fluctuations in Orthorhombic 3 d 1 Perovskites

University of Pavia, Ticinum, Lombardy, Italy
(Impact Factor: 7.51). 05/2004; 92(17):176403. DOI: 10.1103/PhysRevLett.92.176403
Source: PubMed

ABSTRACT

Using ${t}_{2g}$ Wannier functions, a low-energy Hamiltonian is derived for orthorhombic $3{d}^{1}$ transition-metal oxides. Electronic correlations are treated with a new implementation of dynamical mean-field theory for noncubic systems. Good agreement with photoemission data is obtained. The interplay of correlation effects and cation covalency (${\mathrm{GdFeO}}_{3}$-type distortions) is found to suppress orbital fluctuations in ${\mathrm{LaTiO}}_{3}$ and even more in ${\mathrm{YTiO}}_{3}$, and to favor the transition to the insulating state.

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• "4d 1 systems usually have a reduced SOC and some enhanced correlation strengths. In 3d systems, a much stronger correlation strength leads to a Mott transition, which has been intensively discussed,[8] while SOC is usually minor. Here, we focus on the recently synthesized BaFe 2 (PO 4 ) 2 compound with a honeycomb lattice of high spin d 6 Fe 2+ ions, leading to an effectively isolated minority-spin d 1 configuration due to a large exchange splitting of the high spin Fe ion. "
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