| 摘要 |
PROBLEM TO BE SOLVED: To provide a solid solution type electroconductive niobate containing a transition metal, and to provide a method of producing the same. SOLUTION: This is a perovskite type tetragonal niobate material having electroconductivity of 0.01 to 10 Ωm and allowing the switching of electroconductive characteristic between n-type and p-type corresponding with metal species in a solid solution, which comprises a niobate, a transition metal (Mn, Fe, Cu, Ni, Co) and an alkaline earth metal (Ca, Sr, Ba), and if necessary, a rare earth metal (La, Ce, Eu or the like) and is expressed by a formula A0.8-αBαNbO3-δ (α is 0-0.2, A is an alkaline earth metal of Ca, Sr or Ba, or a rare earth metal, and B is a transition metal) or a formula (A, B)xNbO3 (x<=1). The method of producing the tetragonal niobate material in which a transition metal is uniformlydissolved to form a solid solution comprises the steps of mixing under agitation an aqueous alkylamines with a precursor solution in which niobium oxalate, a soluble transition metal and an alkaline earth metal salt, and if necessary, a soluble rare earth metal salt are uniformly solved in water, forming a precipitate, and calcining the obtained precipitate at 900 to 1100 deg.C in air. |
