Piezoelectric material and production method therefor

Abstract

Provided is an oriented piezoelectric material with satisfactory sintering property free of Pb that is a hazardous substance, and a water-soluble alkaline ion, and a production method therefor. To this end, provided is a compound, including a tungsten bronze structure metal oxide, in which: the tungsten bronze structure metal oxide contains at least metal elements of Ba, Bi, Ca, and Nb, the metal elements satisfying the following conditions in terms of molar ratio; and has a C-axis orientation. The compound shows Ba/Nb=a: 0.363<a<0.399, Bi/Nb=b: 0.0110<b<0.0650, and Ca/Nb=c: 0.005<c<0.105. The tungsten bronze structure metal oxide preferably includes (1-x)·Ca 1.4 Ba 3.6 Nb 10 O 30 -x·Ba 4 Bi 0.67 Nb 10 O 30 (0.30≦x≦0.95).

1 . A compound, comprising a tungsten bronze structure metal oxide free from Pb and alkali,
 wherein: the tungsten bronze structure metal oxide contains at least metal elements of Ba, Bi, Ca, and Nb, the metal elements satisfying the following conditions in terms of molar ratio; and has a C-axis orientation:   Ba/Nb=a: 0.363<a<0.399;   Bi/Nb=b: 0.0110<b<0.0650; and   Ca/Nb=c: 0.005<c<0.105 and   wherein the tungsten bronze structure metal oxide comprises (1-x)·Ca 1.4 Ba3.6Nb 10 O 30 -x·Ba 4 Bi 0.67 Nb 10 O 30  (0.30≦x≦0.95).   
     
     
         2 . (canceled) 
     
     
         3 . TheA compound according to  claim 1 , wherein the tungsten bronze structure metal oxide has a Lotgering factor F, which indicates an orientation degree of a diffraction peak (001), of 0.30 or more and 1.00 or less in an X-ray diffraction method. 
     
     
         4 . A piezoelectric material, comprising the compound according to  claim 1 . 
     
     
         5 . A production method for a compound, comprising:
 (A) providing a slurry in which powder of a tungsten bronze structure metal oxide free from Pb and alkali obtained by forming a solid solution of at least metal elements of Ba, Bi, Ca, and Nb is dispersed;   (B) providing a molded body by placing the slurry on a base, orienting the slurry by subjecting the slurry to rotational magnetic field treatment, and then drying the slurry; and   (C) sintering the molded body.   
     
     
         6 . The A-production method according to  claim 5 , wherein a surface of the base in the (B) providing a molded body has an undercoat layer formed of a tungsten bronze structure metal oxide obtained by forming a solid solution of at least metal elements of Ba, Bi, Ca, and Nb. 
     
     
         7 . The production method for a compound according to  claim 5 , wherein a surface of the base in the (B) providing a molded body has an undercoat layer formed of a tungsten bronze structure metal oxide obtained by forming a solid solution of at least metal elements of Ba, Bi, Ca, Nb, and Mn. 
     
     
         8 . The production method for a compound according to  claim 6 , wherein the undercoat layer is oriented. 
     
     
         9 . A piezoelectric element, comprising the piezoelectric material according to  claim 4  sandwiched between a pair of electrodes.