Magnetic and Orbital States and Their Phase Transition of the Perovskite-Type Ti Oxides: Strong Coupling Approach

Masahito Mochizuki, Masatoshi Imada

研究成果: Article

30 引用 (Scopus)

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The properties and mechanism of the magnetic phase transition of the perovskite-type Ti oxides, which is driven by the Ti-O-Ti bond angle distortion, are studied theoretically by using the effective spin and pseudospin Hamiltonian with strong Coulomb repulsion. It is shown that the A-type antiferromagnetic (AFM(A)) to ferromagnetic (FM) phase transition occurs as the Ti-O-Ti bond angle is decreased. Through this phase transition, the orbital state changes only little whereas the spin-exchange coupling along the c-axis is expected to change from positive to negative nearly continuously and approaches zero at the phase boundary. The resultant strong two-dimensionality in the spin coupling causes rapid suppression of the critical temperature, as observed experimentally. It may induce large quantum fluctuations in this region.

元の言語English
ページ(範囲)1777-1789
ページ数13
ジャーナルjournal of the physical society of japan
70
発行部数6
DOI
出版物ステータスPublished - 2001 6 1

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

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