Abstract: Dielectric ceramic composition consisting essentially of substance selected from those represented by the following formulas:(1) Pb.sub.a (Mg.sub.1/3 Nb.sub.2/3).sub.x Ti.sub.y (Ni.sub.1/2 W.sub.1/2).sub.z O.sub.2+a(2) Pb.sub.a Ca.sub.b (Mg.sub.1/3 Nb.sub.2/3).sub.x Ti.sub.y (Ni.sub.1/2 W.sub.1/2).sub.z O.sub.2+a+b(3) Pb.sub.a Ba.sub.b (Mg.sub.1/3 Nb.sub.2/3).sub.x Ti.sub.y (Ni.sub.1/2 W.sub.1/2).sub.z O.sub.2+a+b(4) Pb.sub.a Sr.sub.b (Mg.sub.1/3 Nb.sub.2/3).sub.x Ti.sub.y (Ni.sub.1/2 W.sub.1/2).sub.z O.sub.2+a+bwherein x+y+z=1.00, and a or a+b.gtoreq.1.001.These compositions can be sintered below 1080.degree. C. in low partial pressure of oxygen of about 1.times.10.sup.-8, and exhibit a high dielectric constant and a high electrical resistivity.

Abstract: A dielectric ceramic composition consisting essentially of:PbTi.sub.x (Mg.sub.1/3 Nb.sub.2/3).sub.y (Ni.sub.1/2 W.sub.1/2).sub.z O.sub.3wherein x+y+z=1, which allows low-temperature sintering and has a high dielectric constant, a low dielectric loss and a high specific resistivity.

Abstract: Plural number of thermo-plastic organic films having ceramic green layer(s) and a layer to become electrode thereon are laminated, thereby to form laminated body, which is hot-pressed to impregnate the organic film substance into the ceramic green layers and into layers to become electrodes, and then is fired; thereby, the ceramic layers are formed very thin, thereby producing a capacitor of large capacitance per volume.

Abstract: A dielectric ceramic composition consisting essentially of:Pb(M.sub.1/3 Nb.sub.2/3).sub.x (M'.sub.a Nb.sub.1-a).sub.y (Fe.sub.2/3 W.sub.1/3).sub.z O.sub.3,wherein M represents Ni or Mg and x+y+z=1, andwhen M is Ni, M'=Fe, a=1/2, 0.01.ltoreq.x.ltoreq.0.40, 0.45.ltoreq.y.ltoreq.0.80 and 0.05.ltoreq.z.ltoreq.0.50; andwhen M is Mg, M'=Zn, a=1/3, 0.01.ltoreq.x.ltoreq.0.70, 0.15.ltoreq.y.ltoreq.0.45 and 0.05.ltoreq.z.ltoreq.0.60.The ceramic composition allows low-temperature sintering and exhibits high dielectric constant.

Abstract: A dielectric ceramic composition consisting essentially of Pb(Mg.sub.1/3 Nb.sub.2/3).sub.x (Zn.sub.1/3 Nb.sub.2/3).sub.y (Fe.sub.2/3 W.sub.1/3).sub.z O.sub.3, wherein x+y+z=1, and further containing MnO.sub.2 in amount of 0.05 to 1.0 weight %.

Abstract: A dielectric ceramic composition consisting essentially of a solid solution represented by the formula:xBaO-yTiO.sub.2 -z{(Sm.sub.2 O.sub.3).sub.1-(v+u) (Pr.sub.2 O.sub.11/3).sub.v (Nd.sub.2 O.sub.3).sub.u }wherein 0.05.ltoreq.x.ltoreq.0.23, 0.57.ltoreq.y.ltoreq.0.825, 0.025.ltoreq.Z.ltoreq.0.375, x+y+z=1, 0<v.ltoreq.0.95, 0.ltoreq.u<0.95 and 0<(v+u).ltoreq.0.95.The dielectric ceramics exhibits high dielectric constant and low microwave loss with high temperature stability in resonant frequency and is suitable for use as dielectric resonators, electrical filters and substrate.

Abstract: Ceramic materials within particular ranges of the ternary system Pb(Sn.sub.1/3 Sb.sub.2/3) O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3 in solid solution form exhibit high planar coupling coefficient along with high dielectric constant, and are useful in electromechanical transducers. The ceramic materials are those within the area A, B, C, D, E and F of FIG. 2.

Abstract: A dielectric ceramic consisting essentially of at least 88 weight % of a main component and up to 12 weight % of stannic oxide (SnO.sub.2), said main component consisting essentially of 34.5 to 82 weight % of titanium oxide (TiO.sub.2), 9 to 63 weight % of Praseodymium oxide (Pr.sub.6 O.sub.11) and 2.5 to 23.5 weight % of barium oxide (BaO), at most 95 weight % of said praseodymium oxide being replaceable by neodymium oxide (Nd.sub.2 O.sub.3).It exhibits large dielectric constant and low microwave loss with large temperature-stability for resonant frequency and it is suitable for use as dielectric resonators, electrical filters, substrates, etc.

Abstract: A dielectric ceramic consisting essentially of a solid solution represented by the formula:xBaO--yTiO.sub.2 --zSm.sub.2 O.sub.3wherein 5.ltoreq.x.ltoreq.23, 57.ltoreq.y.ltoreq.82.5, 2.5.ltoreq.z.ltoreq.37.5, and x+y+z=100.The dielectric ceramic exibits large dielectric constant and low microwave loss with high temperature-stability in resonant frequency and is suitable for use as dielectric resonators, electrical filters, substrates and other uses.

Abstract: A dielectric ceramic having a composition expressible by (1-w) (xBaO.multidot.yNa.sub.2 O.multidot.zNb.sub.2 O.sub.5)+wMeO.multidot.ZrO.sub.2 wherein Me denotes Ca or Sr, 0.593.ltoreq.x.ltoreq.0.762, 0.04.ltoreq.y.ltoreq.0.13, 0.174.ltoreq.z.ltoreq.0.32, x+y-z=1, and 0<w.ltoreq.0.95. It exhibits large dielectric constant and low microwave loss with high temperature-stability for resonant frequency and is suitable for use as dielectric resonators, electrical filters, substrates, etc.

Abstract: A piezoelectric ceramic elements obtained by hot-press sintering a composition expressed by the formula:(1-w)PbTi.sub.1-z Zr.sub.z O.sub.3 +wMnO.sub.2at a temperature of 1050.degree. to 1300.degree. C. under a pressure of 100 to 500 Kg/cm.sup.2 for 0.5 to 24 hours shows a mechanical quality factor of 200 or more and a Poisson's ratio of more than 1/3 and gives a piezoelectric material having a large coupling coefficient which can be processed into a thin sheet having a thickness of 30 .mu.m and is especially suitable as a material for resonators and filters by utilizing its thickness extensional vibration.

Abstract: Piezoelectric ceramic compositions having low dissipation factor, high mechanical quality factor, certain specified electromechanical coupling coefficients and high time stability of resonant resistance, and comprising the ternary system Pb(Sn.sub.1/3 Sb.sub.2/3)O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3 and containing at least one oxide selected from the group consisting of MnO.sub.2, CoO, Cr.sub.2 O.sub.3, Fe.sub.2 O.sub.3 and NiO in a total quantity equivalent to from 0.1 to 5 weight percent.

Abstract: Calcined material having a composition including at least two of the components 3BaO.ZnO.Nb.sub.2 O.sub.5, 3BaO.ZnO.Ta.sub.2 O.sub.5, 3BaO.MgO.Nb.sub.2 O.sub.5, and 3BaO.MgO.Ta.sub.2 O.sub.5 and produced under optimum processing conditions as disclosed is employed for obtaining ceramics having low microwave loss with large dielectric constant and suitable for use as dielectric resonators, electrical filters, substrates, etc.

Abstract: Piezoelectric ceramic compositions having very high mechanical quality factors, high electromechanical coupling coefficients and high durabilities of the piezoelectric constants with cycling of mechanical impact, and comprising the quaternary system Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 -Pb(Mn.sub.1/3 Nb.sub.2/3)O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3.

Abstract: A method of making an electrooptical system including a transparent ferroelectric ceramic element which possesses memory in that a birefringence corresponding to an applied electric field remains after the field is removed. The electrooptical element is hot-pressed from a family of materials which comprises solid solution of the ternary system, lead magnesium niobate-lead titanate-lead zirconate, and the hot-pressed material may additionally contain a small amount of lanthanum oxide (La.sub.2 O.sub.3).

Abstract: Piezoelectric ceramic compositions having very high mechanical quality factors, high electromechanical coupling coefficients and high mechanical strength, and comprising the quaternary system Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 -Pb(Sn.sub.1/3 Nb.sub.2/3)O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3 and containing 0.05 to 5 weight % of MnO.sub.2, and further containing at least one oxide selected from the group consisting of Nb.sub.2 O.sub.5 in 0.3 to 3 weight %, WO.sub.3 in 0.1 to 2 weight % and Sb.sub.2 O.sub.3 in 0.1 to 3 weight % are provided.

Abstract: A process for preparing strengthened ferroelectric ceramics, which comprises sintering ceramic materials and then heat treating the sintered ceramics at a temperature from about 100.degree. to about 400.degree.C lower than the final sintering temperature of ceramics, for about 1 to about 60 hrs., and then cooling at a rate from about 300.degree. to about 10.degree.C per hour. Strengthened ferroelectric ceramics are obtained among the following ferroelectric ceramic compositions:I. pb([B.sub.1 ].sub.A Ta.sub.1.sub.-A)O.sub.3 --PbTiO.sub.3 --PbZrO.sub.3, where [B.sub.1 ] is Mg, Zn, Cd, Sn, Mn, Fe, Co, and Ni when A=1/3 and [B.sub.1 ] is Li and Cu when A=1/4,Ii. pb([B.sub.2 ].sub.B Ta.sub.1.sub.-B)O.sub.3 --Pb([B.sub.3 ].sub.C Ta.sub.1.sub.-C)O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3, where [B.sub.2 ] and [B.sub.3 ], [B.sub.2 ].noteq.[B.sub.3 ], are Mg, Zn, Cd, Sn, Mn, Fe, Co and Ni when B and C=1/3, and [B.sub.2 ] and [B.sub.3 ], [B.sub.2 .noteq.[B.sub.3 ], are Li and Cu when B and C=1/4,Iii. pb([B.sub.1 ].sub.A Ta.

Abstract: A process for preparing strengthened ferroelectric ceramics, which comprises heat treatment of sintered ceramics after sintering of ceramic materials at a temperature range from about 100.degree. to about 400.degree.C. lower than the final sintering temperature of ceramics, holding it for about 1 to about 60 hrs, and then cooling it at a cooling rate from about 300.degree. to about 10.degree.C. per hour. Strengthened ferroelectric ceramics are obtained among the following ferroelectric ceramic compositions:I. pb([B.sub.1 ].sub.A Nb.sub.1-A )O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3, where [B.sub.1 ] is Mg, Zn, Cd, Sn, Mn, Fe, Co and Ni when A=1/3 and [B.sub.1 ] is Li and Cu when A=1/4,Ii. pb([B.sub.2 ].sub.B Nb.sub.1-B )O.sub.3 -Pb([B.sub.3 ].sub.C Nb.sub.1-C )O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3, where [B.sub.2 ] and [B.sub.3 ], [B.sub.2 ].noteq.[B.sub.3 ], are Mg, Zn, Cd, Sn, Mn, Fe, Co and Ni when B and C=1/3, and [B.sub.2 ] and [B.sub.3 ], [B.sub.2 ].noteq.[B.sub.3 ], are Li and Cu when B and C=1.4,Iii. pb([B.sub.