Aqueous zirconium hydroxide complexes

Method t rc) Medium logio reported logio fin, logic X. re-interpreted Reference 

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A complex (NH4)[Zr(02)I 5] H20 was crystallized from a solution made by dissolving freshly prepared hydrated zirconium hydroxide in cold (—5°C) 40% hydrofluoric acid, then adding excess 30% hydrogen peroxide, and finally aqueous ammonia until pH 7 is reached. The infrared spectrum showed vq q at 839w, at 555w, and at 480s, br (226). 

Since alkoxides of low formal charge metals are highly condensed and therefore poorly reactive, the synthesis of many perovskites (ticanium. zirconium, niobium, barium, strontium or lead) can take place by hydrolysis of the alkoxide by an aqueous suspension of hydroxide (Ba, Sr) [121] or by an aqueous solution of a lead complex such as the acetate [122]. Iron is introduced as acetylacetonate in the case of PbFeo.jNbo.sOi [123]. The calcination temperature varies with the nature of the metallic cation. It must be adjusted if the formation of undesirable phases is possible, such as the pyrochlore phase in the case of PbMgo.33Nbo.66O3 and PbZri, (Ti 03 [122]. A fast ramp rate prevents or minimizes its formation. 

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