The invention relates to a process for the preparation of a dental restoration, in which an oxide ceramic material is (a) subjected to at least one heat treatment, and (b) cooled, wherein the cooling comprises (b1) a first cooling step with the cooling rate T1 and (b2) a second cooling step with the cooling rate T2 and wherein the absolute value of the cooling rate T2 is less than the absolute value of the cooling rate T1.

A dielectric composition that contains a first complex oxide represented by (Bi.sub.xNa.sub.1−x)TiO.sub.3—CaTiO.sub.3 and having a perovskite structure as a main component; and at least one second complex oxide having a perovskite structure selected from the group consisting of BaZrO.sub.3, SrZrO.sub.3, CaZrO.sub.3, NaNbO.sub.3, and NaTaO.sub.3 as an auxiliary component. A tolerance factor t when the at least one second complex oxide is BaZrO.sub.3, NaNbO.sub.3, or NaTaO.sub.3 is 0.9016≤t≤0.9035, a tolerance factor t when the at least one second complex oxide is SrZrO.sub.3 is 0.9005≤t≤0.9025, and a tolerance factor t when the at least one second complex oxide is CaZrO.sub.3 is 0.9000 t<0.9020.

A piezoelectric ceramic, which does not contain lead as a constituent element, is characterized in that: its primary component is a perovskite compound expressed by the composition formula (Bi.sub.0.5−x/2Na.sub.0.5−x/2Ba.sub.x)(Ti.sub.1−yMn.sub.y)O.sub.3 (where 0.01≤x≤0.25, 0.001≤y≤0.020); and the coefficient of variation (CV) in grain size among the grains contained therein is 35 percent or lower. The piezoelectric ceramic presents an improved dielectric loss tangent tan δ.

In an embodiment a ceramic material includes ZnO as main constituent, Y as a first additive, second additives including at least one compound containing a metal element, wherein the metal element is selected from the group consisting of Bi, Cr, Co, Mn, Ni and Sb, Si.sup.4+ as a first dopant and second dopants having at least one compound containing a metal cation from Al.sup.3+, B.sup.3+, or Ba.sup.2+, wherein a corresponds to a molar proportion of Bi calculated as Bi.sub.2O.sub.3, b corresponds to a molar proportion of Y calculated as Y.sub.2O.sub.3, c corresponds to a molar proportion of Al calculated as Al.sub.2O.sub.3, d corresponds to a molar proportion of Ba calculated as BaO, e corresponds to a molar proportion of B calculated as B.sub.2O.sub.3, f corresponds to a molar proportion of Si calculated as SiO.sub.2, g corresponds to a molar proportion of Ni calculated as NiO, h corresponds to a molar proportion of Co calculated as Co.sub.3O.sub.4, i corresponds to a molar proportion of Cr calculated as Cr.sub.2O.sub.3, j corresponds to a molar proportion of Sb calculated as Sb.sub.2O.sub.3, and k corresponds to a molar proportion of Mn calculated as Mn.sub.3O.sub.4.

This ferrite magnet has a magnetoplumbite structure and is characterized in that, when representing the composition ratios of the total of each metal element A, R, Fe and Me with expression (1) A.sub.1-xR.sub.x(Fe.sub.12-yMe.sub.y).sub.z, the Fe.sup.2+ content (m) in the ferrite magnet is greater than 0.1 mass % and less than 5.4 mass % (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn). The invention makes it possible to achieve a ferrite magnet with increased Br.

Disclosed herein are embodiments of low temperature co-fireable scheelite materials which can be used in combination with high dielectric materials, such as nickel zinc ferrite, to form composite structures, in particular for isolators and circulators for radiofrequency components. In some embodiments, the scheelite material can include aluminum oxide for temperature expansion regulation.

Disclosed herein are embodiments of low temperature co-fireable dielectric materials which can be used in conjunction with high dielectric materials to form composite structures, in particular for isolators and circulators for radiofrequency components. Embodiments of the low temperature co-fireable dielectric materials can be scheelite or garnet structures, for example, bismuth vanadate. Adhesives and/or glue is not necessary for the formation of the isolators and circulators.

A piezoelectric material composition, a method of manufacturing the same, a piezoelectric device, and apparatus including the piezoelectric device. The piezoelectric device may include a piezoelectric device layer including a first material and a second material surrounded by the first material, a first electrode portion disposed at a first surface of the piezoelectric device layer, and a second electrode portion disposed at a second surface of the piezoelectric device layer opposite to the first surface, wherein the piezoelectric device layer comprises a piezoelectric material composition represented by Chemical Formula 1: 0.96(Na.sub.aK.sub.1-a)(Nb.sub.b(T.sub.1-b))O.sub.3-(0.04-x)MZrO.sub.3-x(Bi.sub.cAg.sub.1-c)ZrO.sub.3+d mol % NaNbO.sub.3, wherein T is Sb or Ta, M is Sr, Ba or Ca, a is 0.4≤a≤0.6, b is 0.90≤b≤0.98, c is 0.4≤c≤0.6, d is 0≤d≤5.0, and x is 0≤x≤0.04 and wherein T is Sb or Ta and M is Sr, Ba, or Ca.

A light-emitting ceramic that includes a pyrochlore type compound that contains 0.01 mol % or more of Bi with respect to 100 mol % of the general formula M1.sub.XM2.sub.YM3.sub.ZO.sub.W, wherein M1 is at least one of La, Y, Gd, Yb, and Lu, M2 is at least one of Zr, Sn, and Hf, M3 is at least one of Ta, Nb, and Sb, X, Y, Z, and W are positive numbers that maintain electrical neutrality, X+Y+Z=2.0, 0.005≤Z≤0.2, and 3X+4Y+5Z is 7.02 or less.

Process for treating a porous dental zirconia block with a coloring solution, the process comprising the steps of providing a porous dental zirconia block having two opposing surfaces, surface U and surface L, treating the upper surface U of the porous dental zirconia block with a coloring solution A.sub.1, wherein the coloring solution is provided with a volume VA.sub.1, turning the porous dental zirconia block around, treating the lower surface L with a coloring solution A.sub.2 which is provided with a volume VA.sub.2. wherein the coloring solutions A.sub.1 and A.sub.2 comprise a solvent and coloring ions, wherein the volume of at least one of the coloring solutions A.sub.1 or A.sub.2 is applied in portions, wherein the following condition is met: Vo=ΣV.sub.AX, with x≥2, with Vo being the overall amount of coloring solution used to infiltrate the porous dental zirconia block.