Provided is at least one of a zirconia sintered body and a method for producing the same. The zirconia sintered body can be used in a wide range of applications compared with ceramic joined bodies of the related art that include transparent zirconia. A zirconia sintered body includes a transparent zirconia portion and an opaque zirconia portion, wherein the zirconia sintered body has a biaxial flexural strength of greater than or equal to 300 MPa.

Provided is a silicate glass, a method for preparing a silicate glass-ceramics by using the silicate glass, and a method for preparing a lithium disilicate glass-ceramics by using the silicate glass, and more particularly, to a method for preparing a glass-ceramics that has a nanosize of 0.2 to 0.5 μm and contains lithium disilicate and silicate crystalline phases. A nano lithium disilicate glass-ceramics containing a SiO.sub.2 crystalline phase includes: a glass composition including 70 to 85 wt % SiO.sub.2, 10 to 13 wt % Li.sub.2O, 3 to 7 wt % P.sub.2O.sub.5 working as a nuclei formation agent, 0 to 5 wt % Al.sub.2O.sub.3 for increasing a glass transition temperature and a softening point and enhancing chemical durability of glass, 0 to 2 wt % ZrO.sub.2, 0.5 to 3 wt % CaO for increasing a thermal expansion coefficient of the glass, 0.5 to 3 wt % Na.sub.2O, 0.5 to 3 wt % K.sub.2O, and 1 to 2 wt % colorants, and 0 to 2.0 wt % mixture of MgO, ZnO, F, and La.sub.2O.sub.3.

Provided is a silicate glass, a method for preparing a silicate glass-ceramics by using the silicate glass, and a method for preparing a lithium disilicate glass-ceramics by using the silicate glass, and more particularly, to a method for preparing a glass-ceramics that has a nanosize of 0.2 to 0.5 μm and contains lithium disilicate and silicate crystalline phases. A nano lithium disilicate glass-ceramics containing a SiO.sub.2 crystalline phase includes: a glass composition including 70 to 85 wt % SiO.sub.2, 10 to 13 wt % Li.sub.2O, 3 to 7 wt % P.sub.2O.sub.5 working as a nuclei formation agent, 0 to 5 wt % Al.sub.2O.sub.3 for increasing a glass transition temperature and a softening point and enhancing chemical durability of glass, 0 to 2 wt % ZrO.sub.2, 0.5 to 3 wt % CaO for increasing a thermal expansion coefficient of the glass, 0.5 to 3 wt % Na.sub.2O, 0.5 to 3 wt % K.sub.2O, and 1 to 2 wt % colorants, and 0 to 2.0 wt % mixture of MgO, ZnO, F, and La.sub.2O.sub.3.

A zirconia sintered body that includes a transparent zirconia portion and an opaque zirconia portion has a biaxial bending strength of 300 MPa or more. In addition, the opaque zirconia portion is configured by an opaque zirconia sintered body that is any one of a dark-colored zirconia sintered body, a medium-light-colored zirconia sintered body, and a light-colored zirconia sintered body.

A ferrite sintered body contains Fe, Mn, Zn, Cu, and Ni. Supposing that Fe, Mn, Zn, Cu, and Ni are converted into Fe.sub.2O.sub.3, Mn.sub.2O.sub.3, ZnO, CuO, and NiO, respectively, and the sum of the contents of Fe.sub.2O.sub.3, Mn.sub.2O.sub.3, ZnO, CuO, and NiO is 100 mol %, the sum of the contents of Fe.sub.2O.sub.3 and Mn.sub.2O.sub.3 is 48.47 mol % to 49.93 mol %, the content of Mn.sub.2O.sub.3 is 0.07 mol % to 0.37 mol %, the content of ZnO is 28.95 mol % to 33.50 mol %, and the content of CuO is 2.98 mol % to 6.05 mol %. Furthermore, 102 ppm to 4,010 ppm Zr in terms of ZrO.sub.2 and 10 ppm to 220 ppm Al in terms of Al.sub.2O.sub.3 are contained per 100 parts by weight of the sum of the amounts of contained Fe.sub.2O.sub.3, Mn.sub.2O.sub.3, ZnO, CuO, and NiO.

A modification layer on a surface of a ceramic substrate, includes, in parts by mass: 56 to 67.5 parts of silicon dioxide; 12 to 18 parts of aluminum oxide; and 2.8 to 5.5 parts of lithium oxide. In an embodiment, the modification layer further includes, in parts by mass: at least one of 1.8 to 2.8 parts of phosphorus pentoxide; 0.5 to 2.0 parts of calcium oxide; 0.15 to 1.5 parts of magnesium oxide; and 2.5 to 5.25 parts of barium oxide.

A ferrite sintered body contains Fe, Mn, Zn, Cu, and Ni. Supposing that Fe, Mn, Zn, Cu, and Ni are converted into Fe.sub.2O.sub.3, Mn.sub.2O.sub.3, ZnO, CuO, and NiO, respectively, and the sum of the contents of Fe.sub.2O.sub.3, Mn.sub.2O.sub.3, ZnO, CuO, and NiO is 100 mol %, the sum of the contents of Fe.sub.2O.sub.3 and Mn.sub.2O.sub.3 is 48.47 mol % to 49.93 mol %, the content of Mn.sub.2O.sub.3 is 0.07 mol % to 0.37 mol %, the content of ZnO is 28.95 mol % to 33.50 mol %, and the content of CuO is 2.98 mol % to 6.05 mol %. Furthermore, 102 ppm to 4,010 ppm Zr in terms of ZrO.sub.2 and 10 ppm to 220 ppm Al in terms of Al.sub.2O.sub.3 are contained per 100 parts by weight of the sum of the amounts of contained Fe.sub.2O.sub.3, Mn.sub.2O.sub.3, ZnO, CuO, and NiO.

A dielectric composition includes a main phase and a Ca—Si—P—O segregation phase. The main phase includes a main component expressed by ABO.sub.3. “A” includes at least one selected from calcium and strontium. “B” includes at least one selected from zirconium, titanium, hafnium, and manganese. The Ca—Si—P—O segregation phase includes at least calcium, silicon, and phosphorus.

The present invention relates to a paste-type composition for a fused deposition modeling (FDM) 3D printer comprising: a ceramic powder including CaO and SiO.sub.2; and a binder solution, wherein the composition may be injected into the FDM 3D printer in the form of a paste to rapidly manufacture a molded article without a melting process and may precisely implement a variety of geometries to be utilized as a biological replacement for medical use.

A positive electrode active material for a non-aqueous electrolyte secondary battery includes secondary particles of a lithium transition metal complex oxide as a main component. The main component is represented by a formula: Li.sub.t(Ni.sub.1-xCo.sub.x).sub.1-yMn.sub.yB.sub.αP.sub.βS.sub.γO.sub.2, where t, x, y, α, β, and γ satisfy inequalities of 0≤x≤1, 0.00≤y≤0.50, (1−x).Math.(1−y)≥y, 0.000≤α≤0.020, 0.000≤β=0.030, 0.000≤γ≤0.030, and 1+3α+3β+2γ≤t≤1.30, and satisfy at least one of inequalities of 0.002≤α, 0.006≤β, and 0.004≤γ. The secondary particles exhibit a pore distribution, where a pore volume Vp(1) having a pore diameter of not less than 0.01 μm and not more than 0.15 μm satisfies an inequality of 0.035 cm.sup.3/g≤Vp(1) and where a pore volume Vp(2) having a pore diameter of not less than 0.01 μm and not more than 10 μm satisfies an inequality of Vp(2)≤0.450 cm.sup.3/g.