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The mechanism of the precursor dehydration route was revealed for the synthesis of NTE c-ZrW_ 1.6 Mo_ 0.4 O_8. The hydrate precursor was dehydrated at 473 K and transformed to a NTE cubic compound above 800 K. A novel intermediate phase o-ZrW_ 1.6 Mo_ 0.4 O_8 occurs between the temperature range of 573—800 K. The XRD pattern of novel intermediate was refined with the structural model of LT-ZrMo_2O_8 by using Rietveld method. The residuals are R_ wp =7.80% and R_p=5.79%. The space group is Pmn2_1 and the lattice parameters are a=0.5917(4) nm, b=0.7273(4) nm, c=0.9148(6) nm, and Z=2.
The mechanism of the precursor dehydration route was revealed for the synthesis of NTE c-ZrW 1.6 Mo 0.4 O 8. The hydrate precursor was dehydrated at 473 K and transformed to a NTE cubic compound above 800 K. A novel intermediate phase o-ZrW 1.6 Mo 0.4 O_8 occurs between the temperature range of 573-800 K. The XRD pattern of novel intermediate was refined with the structural model of LT-ZrMo_2O_8 by using Rietveld method. The residuals are R_wp = 7.80% and R_p = 5.79%. The space group is Pmn2_1 and the lattice parameters are a = 0.5917 (4) nm, b = 0.7273 (4) nm, c = 0.9148 (6) nm, and Z = 2.