PROCESS

摘要

A process for the preparation of a niobium compound of formula (I): DaNbßE?O-3-d (I) wherein D is an alkali metal (e.g. Li, Na, K, Rb, Cs and/or Fr), alkaline earth metal (such as Ba, Ca, Mg and/or Sr), La and/or Bi and may be present as a mixture of two or more metals; E is Ta, Sb and/or Fe and may be present as a mixture of two or more metals; a is a positive number ß is a positive number ? is zero or a positive number d is a number 0 = d = 0.5; and wherein the formula (I) has the perovskite or tungsten bronze structure; comprising spray pyrolising a solution, for example an aqueous solution, comprising metal (D) ions, Nb ions and if present, metal (E) ions.