Provided are a dielectric, a device including the same, and a method of preparing the dielectric. The dielectric material includes a NaNbO.sub.3 ternary material including a perovskite phase with a Sm element substituted into a Na site such that the NaNbO.sub.3 ternary material has a permittivity of 600 or more at 1 kHz, and a temperature coefficient of capacitance (TCC) of about -15% to about 15% in a range of about -55° C. to about +200° C.

A supported catalyst for decomposing an organic substance that includes a support and a catalyst particle supported on the support. The catalyst particle contains a perovskite-type composite oxide represented by A.sub.xB.sub.yM.sub.zO.sub.w, where the A contains at least one selected from Ba and Sr, the B contains Zr, the M is at least one selected from Mn, Co, Ni and Fe, y+z=1, x≥0.995, z≤0.4, and w is a positive value satisfying electrical neutrality. A film thickness of a catalyst-supporting film supported on the support and containing the catalyst particle is 5 μm or more, or a supported amount as determined by normalizing a mass of the catalyst particle supported on the support by a volume of the support is 45 g/L or more.

A dielectric substance includes a core-shell grain having a twin crystal structure. An interface of the twin crystal structure of the core-shell grain extends from a shell on one side, passes through a core, and extends to the shell on the other side.

A piezoelectric stack, including: a substrate; an electrode film; and a piezoelectric film comprising an alkali niobium oxide of a perovskite structure represented by a composition formula of (K.sub.1-xNa.sub.x)NbO.sub.3 (0<x<1), wherein an average light transmittance through the piezoelectric film in a wavelength region of visible light and near-infrared ray is 65% or more.

Inorganic perovskites doped with oxygen atoms or fluorine atoms, methods for making the doped perovskites, and hard radiation detectors incorporating the doped perovskites as photoactive layers are provided. The doped perovskites utilize lead oxide, lead fluoride, or compounds that thermally decompose into lead oxide or lead fluoride as dopant atom sources. During the crystallization of a perovskite in the presence of the dopant atom sources, oxygen or fluoride atoms from the dopant source are incorporated into the perovskite crystal lattice.

The present disclosure discloses an ABO.sub.3 type high-entropy perovskite Ba.sub.x(FeCoNiZrY).sub.0.2O.sub.3-δ electrocatalytic material and a preparation method thereof, belonging to the technical field of electrocatalytic materials. The electrocatalytic material is prepared by taking hydrated cobalt nitrate, hydrated ferric nitrate, hydrated nickel nitrate, barium nitrate, hydrated yttrium nitrate, hydrated zirconium nitrate and polyacrylonitrile staple fibers as raw materials through processes of liquid phase chelation, gelation, calcination, etc. The prepared high-entropy perovskite Ba.sub.x(FeCoNiZrY).sub.0.2O.sub.3-δ electrocatalytic material can release more electrochemical active sites due to its special nanostructure, thus showing better electrocatalytic activity. Meanwhile, by adjusting the stoichiometric ratio of A/B-site metals, the electronic structure change of five metals in a catalytic center and the change of an oxygen vacancy content are realized, and the purpose of adjusting and optimizing the nitrogen reduction performance is achieved, so that the electrocatalytic material has excellent electrocatalytic conversion of nitrogen gas into ammonia gas.

A multilayer ceramic capacitor includes: a multilayer structure in which ceramic dielectric layers and internal electrode layers are alternately stacked, wherein: a main component of the ceramic dielectric layer is barium titanate in which a donor element having a larger valence than Ti is solid-solved and an acceptor element having a smaller valence than Ti and larger ion radius than Ti and the donor element is solid-solved; a solid-solution amount of the donor element is 0.05 mol or more and 0.3 mol or less on a presumption that an amount of the barium titanate is 100 mol and the donor element is converted into an oxide; and a solid solution amount of the accepter element is 0.02 mol or more and 0.2 mol or less on a presumption that the amount of the barium titanate is 100 mol and the acceptor element is converted into an oxide.

A piezoelectric body contains potassium, sodium, and niobium, and has a perovskite structure. A Raman shift of peaks assigned to A.sub.1g obtained by performing Raman spectroscopic analysis on a plurality of measurement regions is 400 cm.sup.−1 or more and 700 cm.sup.−1 or less. A difference between a maximum value and a minimum value of the Raman shift among the peaks in the plurality of measurement regions is 11.0 cm.sup.−1 or less.

An antimicrobial material including a substrate and an antimicrobial mixed metal oxide, mixed metal sulfide, or mixed metal oxysulfide in and/or on the substrate is described, as well as antimicrobial coating materials and coatings formed therefrom. The antimicrobial material may be constituted in an antimicrobial surface of a surface-presenting substrate, to combat transmission and spread of microbial disease, e.g., disease mediated by microbial pathogens such as bacteria, viruses, and fungi. Antimicrobial mixed metal oxide, mixed metal sulfide, or mixed metal oxysulfide as described may be contacted with microorganisms to effect inactivation thereof.

A composite oxide powder including a composition formula (1), wherein the ratio α/β of a surface area value α(m.sup.2/g) calculated by a BET one-point method to a surface area value β(m.sup.2/g) calculated from a formula (2) is greater than 1.0 and equal to or less than 1.5 and the surface area value α is equal to or less than 20 m.sup.2/g. ABO.sub.3-δ (1) (wherein A is one or more types of elements (La, Sr, Sm, Ca and Ba), B is one or more types of elements (Fe, Co, Ni and Mn) and 0≤δ<1); and surface area value β(m.sup.2/g)=specific surface area value γ- surface area value ε(2) (the specific surface area value γ(m.sup.2/g) is a value in a total pore size range measured by a mercury intrusion method.The specific surface area value ε(m.sup.2/g) is a value in a range of pore sizes that are larger than a 50% cumulative particle size.