An LTCC microwave dielectric material, including the following components: a Ba.sub.5Si.sub.8O.sub.21+(1−a) (Mg.sub.xCa.sub.ySr.sub.zBa.sub.1-x-y-z)WO.sub.4+Ba—B—Si glass; wherein 0.4≤a≤0.8, 0≤x≤1, 0≤y≤1, 0≤z≤1. By adjusting the amounts of Ba.sub.5Si.sub.8O.sub.21 and (Mg.sub.xCa.sub.ySr.sub.zBa.sub.1-x-y-z)WO.sub.4, the temperature coefficient of resonance frequency can be adjusted to nearly zero. The material is suitable for the fields of high-frequency communication and radiofrequency. Also disclosed is a method for preparing the LTCC microwave dielectric material.

A sintered composite ceramic, includes: a lithium-garnet major phase; and a lithium dendrite growth inhibitor minor phase, such that the lithium dendrite growth inhibitor minor phase has a Li-metal oxide in a range of >0-10 wt. % based on the total weight of the sintered composite ceramic.

A composition includes at least one Pb/Ni/Nb - Pb/Mg/W - Pb/Zr/Ti mixed oxide. A piezoelectric device may be made by providing at least two layers comprising the composition and coated with an outer electrode material; providing a plurality of layers comprising the composition and coated with an inner electrode material; combining or stacking a plurality of layers coated with inner electrode materials between two outer electrodes; and sintering or co-firing the inner electrode materials and outer electrode materials at a temperature at or below about 1000° C.

A negative thermal expansion material made of zirconium phosphate tungstate containing an Al atom, and having a thermal expansion coefficient of −2.0×10.sup.−6 to −3.3×10.sup.−6/K. According to the present invention, a negative thermal expansion material made of zirconium phosphate tungstate having various thermal expansion coefficients, and an industrially advantageous manufacturing method thereof can be provided.

The present invention relates to a composite of a cobalt-based perovskite material with a negative thermal expansion material, and a preparation method of the same, and a solid oxide fuel cell (SOFC) comprising the same, and belongs to the technical field of fuel cells. In the present invention, a negative thermal expansion material is introduced into a cobalt-based perovskite oxide to successfully prepare an SOFC cathode material with excellent electrochemical performance and low thermal expansivity. The composite electrode achieves prominent mechanical tolerance in SOFC, which can moderate a volume change during the whole calcination process and enable a smooth transition to a high-temperature stage. The composite electrode has a thermal expansion coefficient (TEC) only of 12.9×10.sup.−6 K.sup.−1, which is perfectly matched with that of an SDC electrolyte. In addition, the composite shows excellent oxygen reduction reaction (ORR) activity, high TEC, and extremely-excellent anti-CO.sub.2 poisoning performance.

Disclosed are embodiments of making a high Q ceramic material. The method includes providing Ba.sub.3CoTa.sub.2O.sub.9 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 Ba.sub.3CoTa.sub.2O.sub.9 to form a solid solution having a high Q value of greater than 12000 at about 10 GHz.

Disclosed are embodiments of making a high Q ceramic material. The method includes providing Ba.sub.3NiTa.sub.2O.sub.9 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 Ba.sub.3NiTa.sub.2O.sub.9 to form a solid solution having a high Q value of greater than 12000 at about 10 GHz.

Disclosed are embodiments of a barium magnesium tantalate including additional components to increase the Q value of the material. In some embodiments, complex tungsten oxides and/or hexagonal perovskite crystal structures can be added into the barium magnesium tantalate to provide for advantageous properties. In some embodiments, no tin is used in the formation of the material.

A negative thermal expansion material made of zirconium phosphate tungstate containing an Al atom, and having a thermal expansion coefficient of −2.0×10.sup.−6 to −3.3×10.sup.−6/K. According to the present invention, a negative thermal expansion material made of zirconium phosphate tungstate having various thermal expansion coefficients, and an industrially advantageous manufacturing method thereof can be provided.

A composition of matter includes an n-type semiconductor. At least a portion of the semiconductor has the crystal structure of the chemical compound represented by FeWO.sub.4. The portion of the semiconductor having the crystal structure of FeWO.sub.4 includes iron and tungsten. A photoanode can have a light-absorbing layer that includes or consists of the semiconductor. A solar fuels generator can include the photoanode.