The mixture of ferroelectric ceramic material for low-frequency capacitors
(57) Abstract:Use: manufacture of ferroelectric ceramic material and the low-frequency capacitors. The inventive mixture contains MgNb2O6, PbTiO3, PbO, MnCO3and CaZrO3(or CaSnO3and BaSnO3). Effect: reduce the complexity of the manufacturing process, the firing temperature of the material and the cost of the capacitors while maintaining high values of the dielectric and electrical properties of the material and products. table 2. The invention relates to the field of ceramic production, in particular to the composition of the charge of ferroelectric ceramic materials, and can be used in a ceramic capacitor manufacturing in the manufacture of low-frequency capacitors.Known ferroelectric ceramic materials for capacitors based niobate magnesium, iron niobate, titanate, and additives (see application UK N 2126575).This material has a relatively high dielectric constant ( 14000) and provides the application for internal electrodes of multilayer capacitors cheaper nl what about it is different enough high complexity of the process of obtaining, and provides no further increase the dielectric constant.The closest in technical essence to the invention is a mixture of ferroelectric ceramic material including Pb(Mg1/3Nb2/3)O3, Pb(Fe1/2Nb1/2)O3, PbTiO3and mn containing additive MnCO3Mn(OH)2H2O (see and.with. USSR N 1364611).Ferroelectric ceramic material on the basis of this charge is designed to produce low frequency capacitors and is characterized by a higher dielectric constant (e 16600 18000) and a wider range of operating temperatures (-60o+125oC) that provides high properties of capacitors based on it.A significant drawback of the material on the basis of this charge is that it is characterized by a high complexity of the process to obtain it, due to the need for firing (sintering) of the workpiece material in a closed volume to prevent evaporation of lead oxide, and is characterized by a high temperature (1220 1250oC) sintering blanks from it, which limits the use as internal electrodes of the multilayer capacitor b is receiving Ag, and this, in turn, does not provide further cost reduction capacitors and higher technical result.The proposed mixture of ferroelectric ceramic material eliminates the disadvantages of the known materials of similar purpose and achieving higher technical result, which consists in reducing the complexity of the manufacturing process, temperature firing (sintering) of the workpiece material and the cost of the capacitors while maintaining a high dielectric constant and other electrical properties of the material and capacitors from it.The invention consists in the fact that in the inventive charge of ferroelectric ceramic material for low-frequency capacitors, including a titanate, and mn containing additive, the above technical result is ensured by the fact that the mixture additionally contains niobate magnesium, oxide of lead and powder zirconates or stannates of CaZrO3, CaSnO3and BaSnO3and as the mn containing additive contains carbon manganese in the following ratio, wt.PbO 66 70
3, CaSnO3and BaSnO30,28 0,5
In this case, reducing the complexity of the manufacturing process, the firing temperature of the billet material and the cost of the capacitors is achieved by the fact that the introduction of the charge of powder zirconates or stannates from a number of CaZrO3and CaSnO3and BaSnO3and carbon manganese in combination with other components eliminates the need for firing blanks in a closed volume, because with regard to the introduction niobate magnesium decreases the firing temperature of the workpieces to 930 960oC and virtually eliminating the evaporation of lead oxide. In addition, the lower temperature firing (sintering) allows you to apply as internal electrodes of multilayer capacitors cheaper alloys of noble metals, such as palladium with 70-85% silver, which significantly reduces the cost of capacitors. When you type in the charge composition carbon manganese (MnCO3) improves elektroparametram (tdBand Rfrommaterial and products. The lead zirconate calcium (CaZrO3or stannat calcium (CaSnO3and stannat barium (BaSnO3) provides the ability to adjust the Curie temperature, and the oxide (PbO) and lead titanate (PbTiO
PbO 66 70
The lead zirconate or stannat from a number of CaZrO3, CaSnO3, BaSnO3- 0,28 0,5 V
SUBSTANCE: invention relates to ceramic materials suitable for use n technical devices to obtain great (up to several tens microns) controlled microdisplacements: actuators, adaptive optics devices, micropositioners. Material, prepared according to standardceramic technology, additionally contains antimony oxide at following proportions of components, wt %: PbO 68.287-68.304, MgO 3.597-3.782, Nb2O5 23.722-24.945, ZrO2 1.599-2.498, TiO2 0.919-1.436, Sb2O3 0.450-0.451.
EFFECT: increased field electrostriction coefficient and reduced material caking temperature.
SUBSTANCE: invention relates to piezoelectric ceramic materials based on lead titanate and can be used in low-frequency receivers - hydrophones, microphones, seismic receivers, as well as in medical diagnosis devices working on a load with low input resistance. The piezoelectric ceramic material based on lead titanate contains lead, niobium, barium, magnesium, nickel and zinc oxides, with the following ratio of components in wt %: PbO 66.58-66.71; Nb2O5 19.17-19.82; TiO2 7.23-7.86%; BaO 2.41-2.42%; MgO 1.89-1.96%; NiO 1.14-1.18; ZnO 0.83-0.86.
EFFECT: material has high piezoelectric modulus and relative permittivity of polarised samples with sufficiently high electromechanical coupling factor of the planar oscillation mode, specific sensitivity, low mechanical Q-factor and sound speed.
2 tbl, 2 ex