A ferroelectric perovskite composition, comprising a perovskite oxide ABO.sub.3, and a doping agent selected from perovskites of Ba(Ni,Nb)O.sub.3 and Ba(Ni,Nb)O.sub.3-δ. The ferroelectric perovskite composition may be represented by the formula: xBa(Ni,Nb)O.sub.3.(1-x)ABO.sub.3 or xBa(Ni,Nb)O.sub.3-δ.(1-x)ABO.sub.3. A method of producing the ferroelectric perovskite composition in thin film form is also provided.

diboride-silicon carbide (SiC) multiphase ceramic, including: (S1) mixing a transition metal oxide mixed powder, nano carbon black and a silicon hexaboride (SiB.sub.6) powder to obtain a precursor powder; and (S2) subjecting the precursor powder to pressureless sintering to obtain the high-entropy carbide-high-entropy diboride-SiC multiphase ceramic with a relative density of 96% or more.

A garnet-type ion-conducting oxide configured to inhibit lithium carbonate formation on the surface of crystal particles thereof, and a method for producing an oxide electrolyte sintered body using the garnet-type ion-conducting oxide. The garnet-type ion-conducting oxide represented by a general formula (Li.sub.x-3y-z, E.sub.y, H.sub.z)L.sub.αM.sub.βO.sub.γ (where E is at least one kind of element selected from the group consisting of Al, Ga, Fe and Si; L is at least one kind of element selected from an alkaline-earth metal and a lanthanoid element: M is at least one kind of element selected from a transition element which be six-coordinated with oxygen and typical elements in groups 12 to 15 of the periodic table; 3≤x−3y−z≤; 0≤y≤0.22; C≤z≤2.8; 2.5≤α≤3.5; 1.5≤≈≤2.5; and 11≤γ≤13), wherein a half-width of a diffraction peak which has a highest intensity and which is observed at a diffraction angle (2θ) in a range of from 29° to 32° as a result of X-ray diffraction measurement using CuKα radiation, is 0.164° or less.

An automated preparation method of a SiC.sub.f/SiC composite flame tube, comprising the following steps: preparing an interface layer for a SiC fiber by a chemical vapor infiltration process, and obtaining the SiC fiber with a continuous interface layer; laying a unidirectional tape on the SiC fiber with the continuous interface layer and winding the SiC fiber with the continuous interface layer to form and obtaining a preform of a net size molding according to a fiber volume and a fiber orientation obtained in a simulation calculation; and adopting a reactive melt infiltration process and the chemical vapor infiltration process successively for a densification and obtaining a high-density SiC.sub.f/SiC composite flame tube in a full intelligent way. The SiC.sub.f/SiC composite flame tube prepared by the present disclosure not only has a high temperature resistance, but also has a low thermal expansion coefficient, high thermal conductivity and high thermal shock resistance.

A method of producing, from a continuous or discontinuous (e.g., chopped) carbon fiber, partially to fully converted metal carbide fibers. The method comprises reacting a carbon fiber material with at least one of a metal or metal oxide source material at a temperature greater than a melting temperature of the metal or metal oxide source material (e.g., where practical, at a temperature greater than the vaporization temperature of the metal or metal oxide source material). Additional methods, various forms of carbon fiber, metal carbide fibers, and articles including the metal carbide fibers are also disclosed.

The present invention provides a niobium oxide sintered compact having a composition of NbO.sub.x (2<x<2.5), and specifically provides a niobium oxide sintered compact which can be applied to a sputtering target for forming a high-quality resistance change layer for use in ReRAM. In particular, the present invention aims to provide a high-density niobium oxide sintered compact suitable for stabilizing the sputtering process.

A piezoelectric material contains: a first component which is a rhombohedral crystal in a single composition, has a Curie temperature Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; a second component which is a crystal other than a rhombohedral crystal in a single composition, has a Curie temperature Tc2 higher than Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; and a third component which is a rhombohedral crystal in a single composition, has a Curie temperature Tc3 equal to or higher than Tc2, and is a lead-free-system composite oxide that has a perovskite-type structure and is different from the first component. When a molar ratio of the third component to the sum of the first component and the third component is α and α×Tc3+(1−α)×Tc1 is Tc4, |Tc4−Tc2| is 50° C. or lower.

A refractory object can include at least 10 wt % Al.sub.2O.sub.3. Further, the refractory object may contain less than approximately 6 wt % SiO.sub.2 or may include a dopant that includes an oxide of Ti, Mg, Ta, Nb, or any combination thereof. In an embodiment, at least approximately 1% of the Al.sub.2O.sub.3 in the refractory object can be provided as reactive Al.sub.2O.sub.3. In another embodiment, the refractory object may have a density of at least approximately 3.55 g/cc, a corrosion rate of no greater than approximately 2.69 mm/year, or any combination of the foregoing. In a particular embodiment, the refractory object can be used to form an Al—Si—Mg glass sheet. In an embodiment, the refractory object may be formed by a process using a compound of Ti, Mg, Ta, Nb, or any combination thereof.

Compounds are generally provided, which may be particularly used to form a layer in a coating system. In one embodiment, the compound may have the formula: A.sub.xB.sub.bLn.sub.1-x-bHf.sub.1-t-dTi.sub.tD.sub.dMO.sub.6, where: A is Al, Ga, In, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Fe, Cr, Co, Mn, Bi, or a mixture thereof; x is about 0.01 to about 0.99; b is 0 to about 0.5, with 1-x-b being 0 to about 0.99 such that Ln is present in the compound; Ln is a rare earth or a mixture thereof that is different than A; t is 0 to about 0.99; D is Zr, Ce, Ge, Si, or a mixture thereof; d is 0 to about 0.5; the sum of t and d is less than 1 such that Hf is present in the compound; and M is Ta, Nb, or a mixture thereof.

An article including a substrate and a plurality of coatings disposed on the substrate is presented. The plurality of coatings includes a thermal barrier coating disposed on the substrate; and a protective coating including a calcium-magnesium-aluminum-silicon-oxide (CMAS)-reactive material disposed on the thermal barrier coating. The CMAS-reactive material has an orthorhombic weberite crystal structure. The CMAS-reactive material is present in the plurality of coatings in an effective amount to react with a CMAS composition at an operating temperature of the thermal barrier coating, thereby forming a reaction product having one or both of melting temperature and viscosity greater than that of the CMAS composition. A method of making the article and a related turbine engine component are also presented.