2003/10/21 by M. N. Iliev, A. P. Litvinchuk, M. V. Abrashev +4 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Electronic and Structural Properties of Oxides #Magnetic and transport properties of perovskites and related materials #Mott insulator #Phonon #Physics #cond-mat.str-el #physics.optics
paper · pdf · doi:10.1103/physrevb.69.172301
4 pages, 5 figures
arxiv created 2003/10/21 · openalex publication_date 2004/05/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The polarized Raman spectra of stoichiometric LaTiO3 (TN=150K) were measured between 6 and 300 K. In contrast to earlier report on half-metallic LaTiO3.02, neither strong background scattering nor Fano shape of the Raman lines was observed. The high-frequency phonon line at 655cm^\ensuremath-1 exhibits anomalous softening below TN: a signature for structural rearrangement. The assignment of the Raman lines was done by comparison to the calculations of lattice dynamics and the nature of structural changes upon magnetic ordering is discussed. The broad Raman band, which appears in the antiferromagnetic phase, is assigned to two-magnon scattering. The estimated superexchange constant J=15.4\ifmmode±\else\textpm\fi0.4meV is in excellent agreement with the result of neutron-scattering studies.