Magnetoelastic coupling in multiferroicNi3V2O8

Abstract

We measured the infrared-active vibrational modes of the Kagom\'e staircase compound ${\text{Ni}}_{3}{\text{V}}_{2}{\text{O}}_{8}$ as a function of temperature to elucidate magnetoelastic interactions and local structure changes through the series of magnetic-ordering transitions. A detailed analysis of frequency-shift trends demonstrates that the phonons are sensitive to different magnetic states, indicating that the lattice is flexible and coupled to the spin system. Combining this data with an analysis of displacement patterns, we discuss the local distortions in the ferroelectric phase.