| 摘要 |
Complex ceramic oxides of the general formula Mg<SUB>2</SUB>MM'O<SUB>6+x </SUB>where M=Rare metal ion or Yttrium or Lanthanum and M'=Sn, Sb, Zr, Hf, Ta, and Nb; and where -0.5<x<0.5; having a defective pyrochlore structure are useful for active and passive electronic applications, as dielectrics, catalyst sensors, hosts for radioactive waste, etc. This process for the preparation of this class of compounds comprises: (i) mixing the compounds of magnesium, M and M' to get the molar ratio as 2:1:1 (ii) the mixture obtained in step (i) along with a wetting medium may be ball milled or mixed; (iii) the resultant slurry may be dried to obtain dry powder, (iv) the resultant mixture may be heated to a temperature in the range of 1000-1600° C. for the duration ranging from 3 hours to 50 hours, either in a single step or by taking out the reactant after heating, checking for the structure formation and heating again after grinding, if necessary.
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