INFRARED-SPECTRA AND SEEBECK COEFFICIENT OF LNCOO3 WITH THE PEROVSKITE STRUCTURE

The lattice vibrations in LnCoO3 perovskites (Ln = La, Pr, Nd, Sm, Eu, or Gd) have been investigated with reference to the lattice vibration s of the ideal cubic perovskite. These vibrations at room temperature indicate the structural changes with the change in the Ln ion. These f requencies are helpful in estimating the stability of the synthesized LnCoO3 phase. The temperature dependence of vibrational frequencies an d the Seebeck coefficient reveal that the crystal symmetry is unchange d and the spin transition is due to the entropy increase of the 3d ele ctrons with rising temperature. (C) 1994 Academic Press, Inc.