Tailorable thermal expansion and hygroscopic properties of cerium-substituted Y2W3O12 ceramics

Abstract A new series of cerium-substituted Y 2 W 3 O 12 ceramics were first fabricated with the goal of tailoring the thermal expansion and reducing the hygroscopicity. Influence of cerium substitution on the structure, hygroscopicity and thermal expansion property of Y 2 W 3 O 12 ceramics were investigated using XRD, FESEM, HRTEM, XPS, TGA and TMA. Results indicate that the Y 3+ can partly be substituted by Ce 3+ in Y 2- x Ce x W 3 O 12 ceramics and increasing substitution of Y 3+ in Y 2 W 3 O 12 by Ce 3+ results in the crystal structure change from orthorhombic to monoclinic. Single-phase Y 2- x Ce x W 3 O 12 ceramics can be synthesized in the range of 0.0 ≤ x ≤ 0.25 with an orthorhombic Y 2 W 3 O 12 -type crystal structure and 1.0  2 W 3 O 12 -type crystal structure, respectively. As the amount of substituted cerium increases, the hygroscopic phenomenon of Y 2- x Ce x W 3 O 12 is significantly promoted, meanwhile the coefficient of thermal expansion gradually decreases. The linear coefficient of thermal expansion of Y 2- x Ce x W 3 O 12 ceramics can be adjusted from −13.094 × 10 −6  K −1 to 2.327 × 10 −6  K −1 by changing the substituted amount of cerium. Moreover, Y 0.25 Ce 1.75 W 3 O 12 does not absorb moisture in air and shows almost zero thermal expansion from 182 °C to 700 °C and its coefficient of thermal expansion is tested to be −0.820 × 10 −6  K −1 . This low thermal expansion Y 0.25 Ce 1.75 W 3 O 12 material may have great potential applications in manufacturing precision device in many fields.