Interrelation of anisotropy of magnetic properties and magnetodielectric effect in a Cu$_{3}$B$_{2}$O$_{6}$ single crystal

The effect of an external magnetic field on permittivity has been studied in a Cu$_{3}$B$_{2}$O$_{6}$ single crystal with a layered structure in the direction perpendicular to layers ($bc$-planes). It has been found that the appreciable magnetodielectric effect in the temperature range below the Néel temperature ($\approx$ 10 K) takes place only at one magnetic field orientation $\mathbf{H}$ and one crystallographic direction, i.e., $\mathbf{H}\parallel\mathbf{b}$. Such “selectivity” of the magnetodielectric effect correlates with the anisotropic behavior of magnetic properties of the crystal.