FILLER FOR PIEZOELECTRIC MATERIALS, COMPOSITE PIEZOELECTRIC MATERIAL, COMPOSITE PIEZOELECTRIC ELEMENT, FILLER FOR COMPOSITE PIEZOELECTRIC MATERIALS, AND METHOD FOR PRODUCING ALKALI NIOBATE COMPOUND

摘要

A filler for piezoelectric materials, which is characterized by being alkali niobate compound particles wherein: the ratio of the number of moles of potassium to the total number of moles of sodium and potassium in terms of atoms, namely K/(Na + K) is from 0.460 to 0.495; and the ratio of the total number of moles of alkali metal elements to the number of moles of niobium in terms of atoms, namely (Li + Na + K)/Nb is from 0.995 to 1.005. The present invention is able to provide: a filler for piezoelectric materials, which has excellent piezoelectric characteristics; and a composite piezoelectric material which is composed of the filler for piezoelectric materials and a polymer matrix.