Disclosed are embodiments of making a barium magnesium tantalate. The method can include providing barium magnesium tantalate and incorporating one of Ba.sub.2MgWO.sub.6, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.2MgWO.sub.6, Ba.sub.3LaTa.sub.3O.sub.12, Ba.sub.8LiTa.sub.5WO.sub.24, BaLaLiWO.sub.6, Ba.sub.4Ta.sub.2WO.sub.12, Ba.sub.2La.sub.2MgW.sub.2O.sub.12, BaLaLiWO.sub.6, Sr.sub.3LaTa.sub.3O.sub.12, and SrLaTaO.sub.12 into the barium magnesium tantalate to form a solid solution having a high Q value.

Provided is a novel polyoxometalate and a method for producing the polyoxometalate. The polyoxometalate is represented by the compositional formula: M.sub.xO.sub.y in which M is tungsten, molybdenum or vanadium; 4x1000; and 2.5y/x7.

A mixed conductor represented by Formula 1:

A.sub.4+xM.sub.5-yM.sub.yO.sub.12-,Formula 1

wherein, in Formula 1, A is a monovalent cation, M is at least one of a divalent cation, a trivalent cation, or a tetravalent cation, M is at least one of a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, or a hexavalent cation, M and M are different from each other, and 0.3x<3, 0.01<y<2, and 01 are satisfied.

A perovskite material represented by Formula 1:

Li.sub.xA.sub.yM.sub.zO.sub.3-Formula 1 wherein in Formula 1, 0<x1, 0<y1, 0<x+y<1, 0<z1.5, 01, A is H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, or a combination thereof, and M is Ni, Pd, Pb, Fe, Ir, Co, Rh, Mn, Cr, Ru, Re, Sn, V, Ge, W, Zr, Mo, Hf, U, Nb, Th, Ta, Bi, Li, H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Mg, Al, Si, Sc, Zn, Ga, Ag, Cd, In, Sb, Pt, Au, or a combination thereof.

A composite thermistor material, a preparation method and an application thereof. The perovskite structure oxide and the pyrochlorite structure oxide are composite by solid state reaction method, which comprise process of ball milling, drying, and calcining. Then the thermistor ceramics with high temperature resistance and controllable B value are sintered at high temperature after mould forming, then the thermistor disks are coated by platinum paste, and then the platinum wire is welded as the lead wire to form thermistor element. The thermistor of the invention can realize temperature measurement from room temperature to 1000 C. and has good negative temperature coefficient thermistor characteristics. The thermistor coefficient B can be adjusted by changing the two-phase ratio to meet the requirements of different systems.

The present invention relates to a dielectric ceramic material for resonators, filters, and oscillators being used in a wireless communication system and, most particularly, to a Ba(Mg.sub.0.5W.sub.0.5)O.sub.3-type high frequency dielectric ceramic material having an appropriate dielectric constant and a high quality factor in a high frequency band and a method for preparing the same. For this, Ba(Mg.sub.0.5W.sub.0.5)O.sub.3 has been chosen as a material having excellent high frequency dielectric properties. At this point, an alkali metal or alkaline earth metal element partly substitutes Barium (Ba), and, for compensation, a metal of a +3 oxidation state is added quantitatively in the place of Magnesium (Mg). Accordingly, a high frequency dielectric ceramic material compound having a high quality factor and a stable temperature property is prepared. When needed, a metal of a +5 oxidation state may be further added quantitatively in the place of Tungsten (W).

As described above, according to the present invention, the high frequency dielectric material has a more appropriate dielectric constant, and an effect of achieving a high quality factor may be expected.

An article comprising a substrate which carries a material of formula (I)

M.sup.1.sub.aM.sup.2.sub.bW.sub.cO.sub.d(P(O).sub.nR.sub.m).sub.e (I)

wherein each of M.sup.1 and M.sup.2 is independently ammonium or a metal cation; a is 0.01 to 0.5; b is 0 to 0.5; c is 1; d is 2.5 to 3; e is 0.01 to 0.75; n is 1, 2 or 3; m is 1, 2 or 3; and R is an optionally substituted hydrocarbyl group.

A material of Formula (I) is provided

M.sub.yT.sub.xQ.sub.vW.sub.1-vO.sub.z-tJ.sub.t (I)

where:
T represents one of tin, lead, antimony and germanium, T being present in the interstitial spaces or voids of the lattice,
M represents one or more species, each selected from the group consisting of (i) metals other than T, and (ii) polyatomic ionic species, said polyatomic species having an ionic radius of no more than 2 , M being present in the interstitial spaces or voids of the lattice,
W is tungsten,
O is oxygen,
Q represents one or more element having an oxidation state of at least +4, Q, if present, occupying a lattice point of W,
J represents one or more non-metallic element anion of chemical valence 1, J, if present, occupying a lattice point of O,
v is from 0 to 1.0, t is from 0 to 3.0, y is non-zero and up to and including 0.32, x is non-zero and up to and including 0.32, and z is from 2.5 to 4, provided that x+y0.33.

The invention relates to a method for preparing a composite metal oxide hollow fibre. A certain stoichiometry of composite metal oxide raw material and a polymer binding agent are added to an organic solvent, and mixed mechanically to obtain an evenly dispersed spinning solution having a suitable viscosity. After defoaming treatment, the spinning solution is extruded through a spinneret and, after undergoing a certain dry spinning process, enters an external coagulation bath; during this period, a phase inversion process occurs and composite metal oxide hollow fibre blanks are formed. The blanks are immersed in the external coagulation bath and the organic solvent is displaced; after natural drying, the blanks undergo a heat treatment process; during this period, polymer burn off, in situ reaction, and in situ sintering processes occur to obtain the composite metal oxide hollow fibre.

A material of Formula (I)

M.sub.yA.sub.xWO.sub.z(I)

where M represents one or more monoatomic species, A represents one or more polyatomic cationic species, each having an ionic radius of no more than 2 , W is tungsten, O is oxygen, y is non-zero and is up to and including 0.32, x is non-zero and up to and including 0.32, and z is from 2.5 to 4.0, provided that x+y0.33.