Dielectric and domain structural properties of $Bi_2Ge_xV_{1-x}O_{5.5-x/2}$ single crystals

Abstract

Single crystals of $Bi_2Ge_xV_{1-x}O_{5.5-x/2}$, with various concentrations of x, have been grown by slowly cooling the melts of $Bi_2O_3, V_2O_5$ and $GeO_2$ in appropriate ratios. Single crystal X-ray diffraction studies confirm their single crystallinity. X-ray powder diffraction studies carried out on crushed single crystals indicate that the compositions corresponding x=0.3 to 0.5 belong to the tetragonal system, while the remaining concentrations of x (0&les;x<0.3 and 1&ges;x>0.5) belong to the orthorhombic system. The polarising microscopic investigations revealed the existence of interesting ferroelectric domain patterns. The dielectric and ferroelectric studies have been done along the c axis of these crystal