Nanosized pure and Cr doped Al2−xInx(WO4)3 solid solutions

For a first time are synthesized nanosized solid solutions with formula Al2−xInxCry(WO4)2 (x = 0–2, y = 0.02–0.1). Co-precipitation method is used for the synthesis. It is established that only by strict maintenance of pH between 2.7 and 2.9 a pure, monophase product of In2(WO4)3 can be obtained. By X-ray powder diffraction and DTA/TG analyses, it is established that at room temperature the solid solutions Al2−xInx(WO4)2 at x value between 0 and 1.1 are orthorhombic and for x value between 1.1 and 2.0 are monoclinic. The phase transition temperatures are defined for different x values. Results from X-ray and TEM analyses show that nanosized pure Al2−xInx(WO4)2 and Cr-doped Al2−xInxCry(WO4)2 with size dimension between 10 and 40 nm can be successfully synthesized by co-precipitation method with subsequent thermal treatment at relatively low temperature (550 °C) for 1 h.