Patent ID: 6413443
Filing Date: 2002-07-02
Classification: C04B,H01L

Abstract:
A piezoelectric ceramic including oxide consisted of a first element, a second element and oxygen, wherein:the first element includes at least lead in the group comprising lead (Pb), calcium (Ca), strontium (Sr) and barium (Ba), the composition is represented by the chemical formula: Pb1âˆ’aAa â€ƒwherein A represents at least one element in the group comprising Ca, Sr and Ba, and a is within a range of 0&lE;a&lE;0.1; the second element includes zinc (Zn), manganese (Mn), titanium (Ti) and zirconium (Zr), and at least niobium in the group comprising niobium (Nb), antimony (Sb) and tantalum (Ta), the composition of these elements is represented by the chemical formula: (Zn1/3/Nb2/3)w(Mn1/3B2/3)xTiyZrz â€ƒwherein B represents at least one element in the group comprising Nb, Sb and Ta, and w, x, y and z are within a range of 0.2&lE;w/x&lE;3.0, 0.1&lE;y&lE;0.5 and 0.2&lE;z&lE;0.6, respectively and w+x+y+z=1; and the composition ratio of the first element to the second element (the first element/the second element) is at least 0.9 and less than 1.0 in the molar ratio.