Method for producing alkali metal niobate particles, and alkali metal niobate particles

Abstract

Disclosed are a method of producing fine particulate alkali metal niobate in a liquid phase system, wherein the size and shape of particles of the fine particulate alkali metal niobate can be controlled; and fine particulate alkali metal niobate having a controlled shape and size. Specifically disclosed are a method of producing particulate sodium-potassium niobate represented by the formula (1): Na x K (1-x) NbO 3 (1), the method including four specific steps, wherein a high-concentration alkaline solution containing Na + ion and K + ion is used as an alkaline solution; and particulate sodium-potassium niobate having a controlled shape and size.

1 - 3 . (canceled) 
     
     
         4 . A particulate sodium-potassium niobate represented by the formula (1):
   Na x K (1-x) NbO 3   (1),
   wherein x is in a range of 0.05≦x≦0.8, and   wherein particles of the particulate sodium-potassium niobate have a maximum diameter of 0.05 to 20 μm and an aspect ratio of 1 to 1.5.   
     
     
         5 . (canceled) 
     
     
         6 . The particulate sodium-potassium niobate according to  claim 4 ,
 wherein a cross-sectional plane of the particles of the particulate sodium-potassium niobate parallel to the longitudinal axis and including the longitudinal axis has substantial line-symmetry with respect to the longitudinal axis,   wherein in the cross-sectional plane, a length from the longitudinal axis to an outline of the particles decreases from an end of the particles on the lateral axis towards an end of the particles on the longitudinal axis, and   wherein a cross-sectional plane of the particles perpendicular to the longitudinal axis has a cross shape.   
     
     
         7 . The particulate sodium-potassium niobate according to  claim 4 ,
 wherein a cross-sectional plane of the particles of the particulate sodium-potassium niobate parallel to the longitudinal axis and including the longitudinal axis has substantial line-symmetry with respect to the longitudinal axis,   wherein in the cross-sectional plane, a length from the longitudinal axis to an outline of the particles decreases from an end of the particles on the lateral axis towards an end of the particles on the longitudinal axis, and   wherein a cross-sectional plane of the particles perpendicular to the longitudinal axis has a substantially circular shape.   
     
     
         8 . (canceled) 
     
     
         9 . A piezoelectric ceramic material comprising the particulate sodium-potassium niobate according to  claim 4 .