Fillers for piezoelectric materials, composite piezoelectric materials and composite piezoelectric elements, fillers for composite piezoelectric materials and methods for producing niobic acid alkali compounds

摘要

(K / (Na + K)) of the number of moles of potassium to the total number of moles of sodium and potassium in terms of atom is 0.460 to 0.495, and the total number of moles of alkali metal elements relative to the number of moles of niobium (Li + Na + K) / Nb) of 0.995 to 1.005. According to the present invention, it is possible to provide a filler for a piezoelectric material having excellent piezoelectric characteristics, and to provide a composite piezoelectric material including a filler for the piezoelectric material and a polymer matrix.