Crystal and magnetic structure of LaTiO3:: Evidence for nondegenerate t2g orbitals -: art. no. 060401

The crystal and magnetic structures of LaTiO3 have been studied by x-ray and neutron-diffraction techniques using nearly stoichiometric samples. We find a strong structural anomaly near the antiferromagnetic ordering T-N=146 K. In addition, the octahedra in LaTiO3 exhibit an intrinsic distortion, which implies a splitting of the t(2g) levels. Our results indicate that LaTiO3 should be considered as a Jahn-Teller system where the structural distortion and the resulting level splitting are enhanced by the magnetic ordering.