The crystal structure and thermal expansion properties of solid solutions Ln2−x Dy x W3O12 (Ln=Er and Y)

Abstract: Crystal structures and thermal expansion properties of solid solutions Ln2−x Dy x W3O12 (Ln=Er and Y) were studied by room and high temperature X-ray diffraction. Rietveld analysis results show that compounds Er2−x Dy x W3O12 with 0≤ x ≤0.7 and Y2−x Dy x W3O12 with 0≤ x ≤1.0 have orthorhombic structures and show negative thermal expansion in temperature range of 200–800°C while compounds Er2−x Dy x W3O12 with 1.2≤ x ≤2.0 and Y2−x Dy x W3O12 with 1.5≤ x ≤2.0 have monoclinic structures and exhibit positive thermal expansion in temperature range of 25–800°C. Thermogravimetric (TG) and differential thermal analysis (DTA) were used to study the hygroscopicity and the phase transition temperature. [Copyright &y& Elsevier]