X-ray diffraction study on surface modified complex strontium titanate microparticles

A novel surface modified complex strontium titanate used as dispersion particles in an electrorhelogical fluid with an extraordinary high yield stress was synthesized by means of a modified sol-gel technique and characterized by X-ray powder diffraction. The structure model free full profile fitting technique was used to derive the crystallographic data of the compound, which crystallized in a monoclinic lattice with a=13.6822(7), b=14.5549(6), c=12.7423(5) A and β=91.803(2) deg. Deliberate examination of the XRD pattern indicates that the most probable space group of the compound is P21/n. A possible composition of the complex strontium titanate is Sr[TiO4(C2O4)2].3H2O with eight chemical formula units per unit cell, leading to a calculated density of DX=2.25 g/cm3 in good agreement with the measured density of Dm=2.28(5) g/cm3