A main object of the present disclosure is to provide a solid electrolyte with high fluoride ion conductivity. The present disclosure achieves the object by providing a solid electrolyte to be used for a fluoride ion battery, the solid electrolyte comprising: a composition of Ce.sub.1-x-yLa.sub.xSr.sub.yF.sub.3-y, in which 0<x, 0<y, and 0<x+y<1; and a crystal phase that has a Tysonite structure.

According to one embodiment, an electrode material is provided. The electrode material includes active material particle containing: a niobium-titanium composite oxide having an average composition in which a molar ratio of niobium to titanium (M.sub.Nb/M.sub.Ti) is greater than 2; and at least one element A selected from the group consisting of potassium, iron and phosphorus. The active material particle contain the element A at a concentration in the range of 100 ppm to 2000 ppm.

Disclosed herein are embodiments of high Q, temperature stable materials with low dielectric constants. In one aspect, a low loss dielectric material includes one or more transition metal oxides based on the (Zn, Ni, Co)O—Al.sub.2O.sub.3—TiO.sub.2 system comprising an aluminate comprising one of cobalt (Co) or nickel (Ni) crystallized in a spinel structure. The low loss dielectric material additionally comprises one or more of: a titanate comprising the one of Co or Ni crystallized in a spinel structure, an aluminum oxide and a titanium oxide crystallized in a rutile structure.

Disclosed are embodiments of synthetic garnet materials for use in radiofrequency applications. In some embodiments, increased amounts of gadolinium can be added into specific sites in the crystal structure of the synthetic garnet by incorporating indium, a trivalent element. By including both indium and increased amounts of gadolinium, the dielectric constant can be improved. Thus, embodiments of the disclosed material can be advantageous in both above and below resonance applications, such as for isolators and circulators.

An oriented apatite-type oxide ion conductor includes a composite oxide expressed as A.sub.9.33+x[T.sub.6.00−yM.sub.y]O.sub.26.0+z, where A represents one or two or more elements selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Be, Mg, Ca, Sr, and Ba, T represents an element including Si or Ge or both, and M represents one or two or more elements selected from the group consisting of B, Ge, Zn, Sn, W, and Mo, and where x is from −1.00 to 1.00, y is from 0.40 to less than 1.00, and z is from −3.00 to 2.00.

A chalcogen-containing compound of the following Chemical Formula 1 which exhibits excellent phase stability at a low temperature, particularly at a temperature corresponding to the driving temperature of a thermoelectric element, and also exhibits an excellent thermoelectric performance index through an increase in a power factor and a decrease in thermal conductivity, a method for preparing the same, and a thermoelectric element including the same:
V.sub.1-xM.sub.xSn.sub.4Bi.sub.2Se.sub.7-yTe.sub.y  [Chemical Formula 1]
In the above Formula 1, V is a vacancy, M is an alkali metal, x is greater than 0 and less than 1, and y is greater than 0 and less than or equal to 1.

Provided is a phosphor which emits near-infrared light upon irradiation of visible light or ultraviolet light. A phosphor in an embodiment of the present invention includes an inorganic substance which contains at least an Eu element, an M[3] element (M[3] is at least one selected from the group consisting of Al, Y, La and Gd.), a Si element and nitrogen element, and also contains, if necessary, at least one element selected from the group consisting of M[1] element (M[1] is Li element.), an M[2] element (M[2] is at least one element selected from the group consisting of Mg, Ca, Ba and Sr.) and an oxygen element, while the phosphor has a maximum value of an emission peak at a wavelength in the range of 760 nm or more and 850 nm and less upon irradiation by an excitation source.

A sulfide solid electrolyte particles comprising lithium, phosphorus and sulfur, having a volume-based average particle size measured by laser diffraction particle size distribution measurement of 0.1 μm to 10 μm, having a diffraction peak having 2θ of 29.0 to 31.0 deg in powder X-ray diffraction measurement using CuKα ray, and an intensity ratio (Ib/Ip) of a peak intensity Ib at a high angle-side low part of the diffraction peak to a peak intensity Ip of the diffraction peak is less than 0.09.

A Ce—Zr composite oxide contains cerium and zirconium, wherein an uneven distribution ratio of cerium atoms is 1.80 or less. A method for producing a Ce—Zr composite oxide includes an acid treatment step of bringing at least one selected from the group consisting of sulfuric acid, nitric acid, and hydrochloric acid, in an amount of 4 to 28 parts by mass with respect to 100 parts by mass of the raw material composite oxide, into contact with the surface of a raw material composite oxide containing cerium and zirconium, and a calcination step of calcining the treated composite oxide obtained in the acid treatment step at 400 to 1200° C. for 5 to 300 minutes.

To a co-precipitating aqueous solution, aqueous solutions containing (a) Tb ions, (b) at least one other rare earth ions selected from the group consisting of Y ions and lanthanoid rare earth ions (excluding Tb ions), (c) Al ions and (d) Sc ions are added; the resulting solution is stirred at a liquid temperature of 50° C. or less to induce a co-precipitate of the components (a), (b), (c) and (d); the co-precipitate is filtered, heated and dehydrated; and the co-precipitate is fired thereafter at from 1,000° C. to 1,300° C., thereby forming a sinterable garnet-type complex oxide powder.