| 摘要 |
A process is disclosed for the preparation of a niobium compound of formula (I):DαNbβEγ03-δ(I) WhereinD 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; E is Ta, Sb and/or Fe;αis a positive numberβis a positive numberγis zero or a positive numberδis a number 0≤δ≤0.5;and wherein the formula (I) has the perovskite or tungsten bronze structure;which process comprises spray-pyrolising a solution, for example an aqueous solution, comprising metal (D) ions, Nb ions and if present, metal (E) ions. The use of the ferroelectric materials formed in piezoelectric devices is disclosed. Also disclosed is a process for the preparation of an alkali metal niobium oxide of the formulaA1-2x-3wBxCwNb1-y-3/5z-uTayFezSbuO3 WhereA is an alkali metal, B is an alkaline earth metalC is La and /or Bi0≤z≤0.3; 0≤u≤0.3; 0≤w≤0.3; 0≤x≤0.3; 0≤y <1 Also disclosed is piezoelectric transformer which comprises a compound of formula ATaO3where A is an alkali metal. |
