Piezoelectric glass ceramic compositions and piezoelectric devices made therefrom
AssigneeSchott AG
InventorMark J. Davis
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Abstract
A piezoelectric glass ceramic represented by the formula (M1Ox)-(M2Oy)—SiO2 wherein M1 is one or more metals and/or metalloids, M2 is one or more metals and/or metalloids, x is a value equal to the valence of M1, and y is a value equal to the valence of M2. The piezoelectric glass ceramic has a total alkali metal concentration of less than about 1000 parts per million by weight (ppmw). A process of preparing a piezoelectric glass ceramic and a piezoelectric glass ceramic body prepared therefrom.
Claims27
A piezoelectric glass ceramic represented by the formula
- (M1Ox)-(M2O)—SiO2
- wherein M1 and M2 are independently one or more metals and/or metalloids, x is a value equal to the valence of M1, and y is a value equal to the valence of M2;
- wherein said piezoelectric glass ceramic has a total alkali metal concentration of less than about 1000 parts per million by weight (ppmw);
- and wherein the piezoelectric glass ceramic is non-ferroelectric.
A piezoelectric glass ceramic represented by the formula
- M3O-M4O2—SiO2
- wherein M3 is one or more Group 2 elements selected from the group consisting of Be, Mg, Ca, Sr and Ba, or a mixture of one or more Group 2 elements selected from the group consisting of Be, Mg, Ca, Sr and Ba with one or more metals and/or metalloids, wherein M4 is one or more Group 4 elements selected from the group consisting of Ti, Zr and Hf, or a mixture of one or more Group 4 elements selected from the group consisting of Ti, Zr and Hf with one or more metals and/or metalloids, wherein said piezoelectric glass ceramic has a total alkali metal concentration of less than about 1000 parts per million by weight (ppmw), and wherein the piezoelectric glass ceramic is non-ferroelectric.
A piezoelectric glass ceramic prepared from a precursor glass body by a ceraming process, the piezoelectric glass ceramic comprising non-ferroelectric piezo-active crystallites precipitated from the precursor glass body, wherein the precursor glass body comprises 55 to 80 wt. % of SiO2, 1 to 40 wt. % of M3O, and 1 to 40 wt. % of M4O2, wherein M3 is one or more Group 2 elements selected from the group consisting of Be, Mg, Ca, Sr and Ba, or a mixture of one or more Group 2 elements selected from the group consisting of Be, Mg, Ca, Sr and Ba with one or more metals and/or metalloids, wherein M4 is one or more Group 4 elements selected from the group consisting of Ti, Zr and Hf, or a mixture of one or more Group 4 elements selected from the group consisting of Ti, Zr and Hf with one or more metals and/or metalloids, wherein the piezoelectric glass ceramic has a total alkali metal concentration of less than about 1000 parts per million by weight (ppmw), and wherein the piezoelectric glass ceramic is non-ferroelectric.
A process of preparing a piezoelectric glass ceramic, said process comprising:
- preparing a precursor glass body which comprises 55 to 80 wt. % of SiO2, 1 to 40 wt. % of (M1Ox) and 1 to 40 wt. % of (M2Oy), wherein M1 and M2 are independently one or more metals and/or metalloids, x is a value equal to the valence of M1, and y is a value equal to the valence of M2, and wherein said precursor glass body has a total alkali metal concentration of less than about 1000 parts per million by weight (ppmw);
- placing the precursor glass body in a furnace in contact with a ceramic fabric having a thermal capacity different from a thermal capacity of the precursor glass body;
- ceraming the precursor glass body within the furnace in contact with the ceramic fabric;
- and
- wherein the piezoelectric glass ceramic is non-ferroelectric.
A process of preparing a piezoelectric glass ceramic, said process comprising:
- preparing a precursor glass body which comprises 55 to 80 wt. % of SiO2, 1 to 40 wt. % of (M1Ox) and 1 to 40 wt. % of (M2Oy), wherein M1 and M2 are independently one or more metals and/or metalloids, x is a value equal to the valence of M1, and y is a value equal to the valence of M2, and wherein said precursor glass body has a total alkali metal concentration of less than about 1000 parts per million by weight (ppmw);
- placing the precursor glass body in a furnace in contact with a brick body having a thermal capacity different from a thermal capacity of the precursor glass body;
- ceraming the precursor glass body within the furnace in contact with the brick body to form the piezoelectric glass ceramic;
- and
- wherein the piezoelectric glass ceramic is non-ferroelectric.
A piezoelectric glass ceramic body prepared from a precursor glass body by placing the precursor glass body in a furnace in contact with a brick body having a thermal capacity from a thermal capacity of the precursor glass body, and ceraming the precursor glass body within the furnace in contact with the brick body;
- wherein the piezoelectric glass ceramic body is non-ferroelectric and contains substantially no alkali metal.
Dependencies are inferred from the claim text.