Zr(WMo)_(1-x/2)V_xO(8-x/2):多元素同/低价取代立方ZrW_2O_8结构类型热收缩固溶体的合成、结构与性质

Zr(WMo)_(1-x/2)V_xO(8-x/2): Synthesis,Structure and Properties of Thermal Contracting Solid Solutions Substituted by Multi-elements with Different Valences in ZrW_2O_8 Type Structure

利用酸蒸气水热法合成了Zr(WMo)1-x/2VxO7-x/2(OH)2·2H2O(x=0.04,0.08,0.10,0.14,0.20,0.22,0.26,0.32)四方晶相固溶体。以此为前驱体,通过高温脱水和相转变法合成了立方相Zr(WMo)1-x/2VxO8-x/2(x=0.04,0.08,0.10,0.14,0.20,0.22)固溶体。立方Zr(WMo)1-x/2VxO8-x/2固溶体具有Pa3空间群。Zr(WMo)1-x/2VxO8-x/2的平均晶体结构描述为按照化学计量的ZrV2O7结构与β-ZrWMoO8结构的叠加。ZrV2O7在立方ZrWMoO8中的固溶度为11mol%;立方Zr(WMo)1-x/2VxO8-x/2固溶体的相变温度低于200 K;在200 K～573 K温度范围内具有负热膨胀系数;线热膨胀系数近似为常数。

The tetragonal precursors, Zr（WMo）1-x/2VxO7-x/2（OH）2·2H2O（x=0.04,0.08,0.10,0.14,0.20,0.22,0.26,0.32） were synthesized by acidic steam hydrothermal （ASH） method, and then the cubic Zr（WMo）1-x/2VxO8-x/2 （x= 0.04, 0.08, 0.10, 0.14, 0.20, 0.22） was prepared from the precursors by high-temperature dehydration and phase transition method. The cubic Zr（WMo）1-x/2VxO8-x/2 possesses the space group Pa3 and the average crystal structures are described stoichiometrically as the superposition of ZrV207 and/3-ZrWMoOs structures with a limited solubility of ZrV2O7 of 11mol% in cubic ZrWMoO8. The cubic Zr（WMo）1-x/2VxO8-x/2 also possesses thermal contraction property at the temperature range of 200~573 K and the linear thermal expansion coefficients are almost the same in the above temperature range. The phase transition temperature for Zr（WMo）1-x/2VxO8-x/2 is lower than 200 K.