Feroelectric ceramics and method for manufacturing the same
To enhance piezoelectric property. One aspect of the present invention is ferroelectric ceramics including a Pb(Zr 1-x Ti x )O 3 film, wherein: the x satisfies the following formula 1, the Pb(Zr 1-x Ti x )O 3 film has a plurality of columnar single crystals, the x axis, the y axis and the z axis of each of the plurality of columnar single crystals are oriented in the same direction, respectively, 0<x<1 formula 1.
1. A ferroelectric ceramic comprising a Pb(Zr 1-x Ti x )O 3 film, wherein:
x satisfies the following formula 1,
0<x<1 formula 1,
the Pb(Zr 1-x Ti x )O 3 film comprises a plurality of columnar single crystals and a PbO wall is formed around each of the plurality of columnar single crystals, and
an x axis, a y axis and a z axis of each of the plurality of columnar single crystals are oriented in a same direction, respectively.
2. The ferroelectric ceramic according to claim 1 , wherein:
the Pb(Zr 1-x Ti x )O 3 film is formed on a Pb(Zr 1-A Ti A )O 3 film,
the A and x satisfy the following formula 2 and formula 3,
0≦A≦0.1 formula 2
A<x formula 3.
3. The ferroelectric ceramic according to claim 1 , wherein a plane z of the z axis has a plane (001).
4. The ferroelectric ceramic according to claim 1 , wherein the Pb(Zr 1-x Ti x )O 3 film has a ratio of elements of Pb:(Zr 1-x +Ti x ) of (1.4 to 1.1):1.
5. The ferroelectric ceramic according to claim 1 , wherein the Pb(Zr 1-A Ti A )O 3 film has a ratio of elements of Pb:(Zr 1-A +Ti A ) of (1.4 to 1.1):1.
6. The ferroelectric ceramic according to claim 1 , wherein:
a Pb(Zr 1-y Ti y )O 3 film is formed on the Pb(Zr 1-x Ti x )O 3 film, and
the Pb(Zr 1-y Ti y )O 3 film has a ratio of elements of Pb:(Zr 1-y +Ti y ) of (1.05 to 1):1, and
the y satisfies the following formula 4,
0<y<1 formula 4.
7. The ferroelectric ceramic according to claim 6 , wherein the ratio of elements of Pb:(Zr 1-y +Ti y ) is 1:1.
8. The ferroelectric ceramic according to claim 1 , wherein:
the A is 0, and
the Pb(Zr 1-A Ti A )O 3 is a PbZrO 3 film.
9. The ferroelectric ceramic according to claim 1 , wherein the Pb(Zr 1-A Ti A )O 3 film is formed on an oxide film.
10. The ferroelectric ceramic according to claim 9 , wherein the oxide film is an SrRuO 3 (SRO) film or an Sr(Ti,Ru)O 3 film.
11. The ferroelectric ceramic according to claim 1 , wherein the Pb(Zr 1-A Ti A )O 3 film is formed on an electrode film.
12. The ferroelectric ceramic according to claim 11 , wherein the electrode film is made of an oxide or a metal.
13. The ferroelectric ceramic according to claim 11 , wherein the electrode film is a Pt film or an Ir film.
14. The ferroelectric ceramic according to claim 11 , wherein the electrode film is formed on a ZrO 2 film.
15. The ferroelectric ceramic according to claim 11 , wherein the electrode film is formed on a Si substrate.
16. A method for manufacturing a ferroelectric ceramic comprising the steps of:
forming, on a substrate, a Pb(Zr 1-A Ti A )O 3 film comprising a plurality of columnar single crystals and a PbO wall formed around each of the plurality of columnar single crystals by coating, onto the substrate, a precursor solution for forming the Pb(Zr 1-A Ti A )O 3 film to which Pb is excessively added by 10 atomic % or more to 40 atomic % or less, and by performing crystallization under a pressurized oxygen atmosphere, and
forming, on the Pb(Zr 1-A Ti A )O 3 film, a Pb(Zr 1-x Ti x )O 3 film comprising a plurality of columnar single crystals and a PbO wall formed around each of the plurality of columnar single crystals by sputtering a sputtering target for the Pb(Zr 1-x Ti x )O 3 having a ratio of elements of Pb:(Zr 1-x +Ti x ) of (1.4 to 1.1):1, wherein
A and x satisfy the following formulas 1 to 3,
0<x<1 formula 1
0≦A≦0.1 formula 2
A<x formula 3.
17. A method for manufacturing a ferroelectric ceramic comprising the steps of:
forming, on a substrate, a Pb(Zr 1-A Ti A )O 3 film comprising a plurality of columnar single crystals and a PbO wall formed around each of the plurality of columnar single crystals by coating, onto the substrate, a precursor solution for forming the Pb(Zr 1-A Ti A )O 3 film to which Pb is excessively added by 10 atomic % or more to 40 atomic % or less, and by performing crystallization under a pressurized oxygen atmosphere, and
forming, on the Pb(Zr 1-A Ti A )O 3 film, a Pb(Zr 1-x Ti x )O 3 film comprising a plurality of columnar single crystals and a PbO wall formed around each of the plurality of columnar single crystals by coating, onto the Pb(Zr 1-A Ti A )O 3 film, a precursor solution for forming the Pb(Zr 1-x Ti x )O 3 film to which Pb is excessively added by 10 atomic % or more to 40 atomic % or less, and by performing crystallization under a pressurized oxygen atmosphere, wherein
A and x satisfy the following formulas 1 to 3,
0<x<1 formula 1
0≦A≦0.1 formula 2
A<x formula 3.
18. The method for manufacturing the ferroelectric ceramic according to claim 16 , further comprising the step of: after the step of forming the Pb(Zr 1-x Ti x )O 3 film, forming a Pb(Zr 1-y Ti y )O 3 film on the Pb(Zr 1-x Ti x )O 3 film by coating, onto the Pb(Zr 1-x Ti x )O 3 film, a precursor solution for forming the Pb(Zr 1-y Ti y )O 3 film to which Pb is excessively added by 0 atomic % or more to 5 atomic % or less, and by performing crystallization under a pressurized oxygen atmosphere, wherein
the y satisfies the following formula 4,
0<y<1 formula 4.
19. The method for manufacturing the ferroelectric ceramic according to claim 18 , wherein a ratio of elements of the Pb:(Zr 1-y +Ti y )O 3 is 1:1.
20. The method for manufacturing the ferroelectric ceramic according to claim 16 , wherein:
the A is 0, and
the Pb(Zr 1-A Ti A )O 3 is a PbZrO 3 film.