Effect of Jahn-Teller distortion on the lattice vibration frequencies of nickel ferrite

Abstract

The infrared spectra of Ni1−xCuxFe2O4 (x=0, 0.1, 0.2) studied at room temperature in the range of 250–800 cm−1 show two main bands. On adding copper to nickel ferrite, the center frequency of these two bands is found to shift to lower energies. The force constants obtained using the center frequency have been observed to increase linearly with the internuclear separation for both the octahedral and tetrahedral sites.