通过控制Zr(Mo,W)(OH,Cl)∙2H₂O的热分解制备具有更大负热膨胀的Zr(Mo,W)O。
Preparation of Zr(Mo,W)O with a larger negative thermal expansion by controlling the thermal decomposition of Zr(Mo,W)(OH,Cl)∙2HO.
作者信息
Petrushina Mariya Yu, Dedova Elena S, Filatov Eugeny Yu, Plyusnin Pavel E, Korenev Sergei V, Kulkov Sergei N, Derevyannikova Elizaveta A, Sharafutdinov Marat R, Gubanov Alexander I
机构信息
Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Academician Lavrentiev Prospekt 3, 630090, Novosibirsk, Russian Federation.
Novosibirsk State University, Pirogova str. 2, 630090, Novosibirsk, Russian Federation.
出版信息
Sci Rep. 2018 Mar 28;8(1):5337. doi: 10.1038/s41598-018-23529-6.
Solid solutions of Zr(Mo,W)O(OH,Cl)∙2HO with a preset ratio of components were prepared by a hydrothermal method. The chemical composition of the solutions was determined by energy dispersive X-ray spectroscopy (EDX). For all the samples of ZrMoWO(OH,Cl)∙2HO (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0), TGA and in situ powder X-ray diffraction (PXRD) studies (300-1100 K) were conducted. For each case, the boundaries of the transformations were determined: Zr(Mo,W)O(OH,Cl)∙2HO → orthorhombic-ZrMoWO (425-525 K), orthorhombic-ZrMoWO → cubic-ZrMoWO (700-850 K), cubic-ZrMoWO → trigonal-ZrMoWO (800-1050 K for x > 1) and cubic-ZrMoWO → oxides (1000-1075 K for x ≤ 1). The cell parameters of the disordered cubic-ZrMoWO (space group Pa-3) were measured within 300-900 K, and the thermal expansion coefficients were calculated: -3.5∙10 - -4.5∙10 K. For the ordered ZrMoWO (space group P23), a negative thermal expansion (NTE) coefficient -9.6∙10 K (300-400 K) was calculated. Orthorhombic-ZrW2O is formed upon the decomposition of ZrWO(OH,Cl)∙2HO within 500-800 K.
采用水热法制备了具有预设组分比例的Zr(Mo,W)O(OH,Cl)∙2H₂O固溶体。通过能量色散X射线光谱（EDX）测定了固溶体的化学成分。对所有ZrMoWO(OH,Cl)∙2H₂O（x = 0.0、0.2、0.4、0.6、0.8、1.0、1.2、1.4、1.6、1.8和2.0）样品进行了热重分析（TGA）和原位粉末X射线衍射（PXRD）研究（300 - 1100 K）。对于每种情况，确定了转变边界：Zr(Mo,W)O(OH,Cl)∙2H₂O → 正交晶系ZrMoWO（425 - 525 K），正交晶系ZrMoWO → 立方晶系ZrMoWO（700 - 850 K），立方晶系ZrMoWO → 三角晶系ZrMoWO（x > 1时为800 - 1050 K）以及立方晶系ZrMoWO → 氧化物（x ≤ 1时为1000 - 1075 K）。在300 - 900 K范围内测量了无序立方晶系ZrMoWO（空间群Pa-3）的晶胞参数，并计算了热膨胀系数：-3.5×10⁻⁶ - -4.5×10⁻⁶ K⁻¹。对于有序的ZrMoWO（空间群P2₁3），计算出负热膨胀（NTE）系数为-9.6×10⁻⁶ K⁻¹（300 - 400 K）。ZrWO(OH,Cl)∙2H₂O在500 - 800 K分解时形成正交晶系ZrW₂O。
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