Temperature-dependent Raman studies of the magnetodielectric vanadates: Ni$_{3}$V$_{2}$O$_{8}$, Co$_{3}$V$_{2}$O$_{8}$, and K$_{2}$V$_{3}$O$_{8}$*

The kagome staircase compounds, Ni$_{3}$V$_{2}$O$_{8}$ and Co$_{3}$V$_{2}$O$_{8}$, are known to exhibit dielectric anomalies at the magnetic transitions; and inhomogenously mixed-valent K$_{2}$V$_{3}$O$_{8}$ has been shown to have a strong dependence of the dielectric constant on applied magnetic field. However, while strong spin-lattice coupling is generally associated with the complex phases and phenomena in these materials, there has been little microscopic information about this coupling. In this talk, we present temperature-dependent Raman scattering studies of Ni$_{3}$V$_{2}$O$_{8}$, Co$_{3}$V$_{2}$O$_{8}$, and K$_{2}$V$_{3}$O$_{8}$ that allow us to investigate the microscopic connection between the strong spin-lattice coupling and the magnetodielectric effects in these materials.