Near-zero thermal expansion of ZrxHf1-xMgMo3O12 in a larger temperature range

ZrxHf1-xMgMo3O12 with x = 0.3, 0.5, 0.7 and 0.8 are developed with a simple solid state method. It is shown that ZrxHf1-xMgMo3O12 (x = 0-1)crystallizes in an orthorhombic symmetry with space group Pnma and exhibits zero-thermal expansion in a large temperature range, with the value of x (x = 0.5, αl =  −0.363 × 10−6 K−1 from 80 K to 573 K by X-ray diffraction and αl =  −0.25 × 10−6 K−1 from 273 K to 673 K by dilatometer). ZrxHf1-xMgMo3O12 with x = 0.5 remains the orthorhombic structure without phase transition or decomposition at least from 158 K to 673 K and is not hygroscopic. These properties make it an excellent material with near-zero thermal expansion for a variety of applications.