Spin–phonon coupling in ferrimagnet spinel CoMn2O4

Abstract

Coupling of material properties provides new fundamental insights and possibilities toward multifunctional devices. The spinel structures display strong coupling between different order parameters, as a consequence, exhibiting many fascinating properties, such as multiferroicity and superconductivity. Here, we have investigated the structural, magnetic, and vibrational properties of mixed-spinel CoMn2O4 stabilized in distorted tetragonal structures as evidenced from x-ray diffraction measurements. Magnetization measurements reveal two ferrimagnetic phase transitions at 185 and 90 K. Raman scattering measurements reveal the renormalization of phonon parameters for a few phonon modes at low temperatures, arising from spin–phonon coupling. The obtained value for λS2 is ∼2 cm−1. The strength of spin–phonon coupling ( λ) is estimated according to the spins involved in the corresponding lattice vibrations and discussed.