共沉淀法合成负热膨胀材料ZrW_2O_8

Synthesize Negative Thermal Expansion Material ZrW_2O_8 Using Co-precipitation Method

Zr W2 O8 是极具应用前景的各向同性负热膨胀材料。用共沉淀法合成了 Zr W2 O8,经 X射线衍射、红外 -拉曼光谱分析证明用共沉淀法合成的 Zr W2 O8纯度高。经高温 X射线衍射测定 ,Zr W2 O8在 2 98～ 973K温度区间线膨胀系数αl =- 7.0× 10 - 6 K- 1 ,α- Zr W2 O8(空间群 P2 1 3)相到β- Zr W2 O8(空间群 Pa3)的转变温度在 4 4 3K与 4 4 6 K之间。对Zr W2 O8前驱体进行了热重 -差热分析 (TG- DTA)

The oxide material ZrW 2O 8 displays unusual property of isotropic negative thermal expansion in a large wide temperature range, which makes it have a number of important potential applications Cubic ZrW 2O 8 was synthesized by co precipitation route X ray diffraction, infrared and Raman spectrum analysis shows the synthesized sample only contains cubic phase of ZrW 2O 8 The precursor of ZrW 2O 8 was studied by using thermogravimetric and differential thermal analysis (TG DTA) High temperature X ray diffraction measurement indicates the linear negative thermal expansion coefficient of ZrW 2O 8 is -7×10 -6 K -1 in the temperature range from 298K to 973K The phase transition temperature from α ZrW 2O 8 to β ZrW 2O 8 is between 443K and 446K