A method of removing fluoride ion from waste liquid is provided, which includes providing a calcium source and a plurality of ceramic particles to a waste liquid containing fluoride ion for forming a plurality of calcium fluoride layers wrapping the ceramic particles. The calcium fluoride layers are connected to form a calcium fluoride bulk. The ceramic particles are embedded in the calcium fluoride bulk. The ceramic particles and the calcium fluoride bulk have a weight ratio of 1:4 to 1:20.

The use of magnesium oxide, reactive alumina and aluminium oxide as a base provides for a new erosion-resistant material upon sintering.

The composite sintered body includes Al.sub.2O.sub.3, and MgAl.sub.2O.sub.4. The content of Al.sub.2O.sub.3 in the composite sintered body is not less than 95.5% by weight. The average sintered grain size of Al.sub.2O.sub.3 in the composite sintered body is not less than 2 μm and not greater than 4 μm. The standard deviation of sintered grain size distribution of Al.sub.2O.sub.3 in the composite sintered body is not greater than 0.35. The bulk density of the composite sintered body is not less than 3.94 g/cm.sup.3 and not greater than 3.98 g/cm.sup.3. In the composite sintered body, the ratio of amount of crystal phase of MgAl.sub.2O.sub.4 to that of Al.sub.2O.sub.3 is not less than 0.003 and not greater than 0.01.

The use of magnesium oxide, reactive alumina and aluminium oxide as a base provides for a new erosion-resistant material upon sintering.

A ceramic material, a component, and a method for producing a component are disclosed. In an embodiment a ceramic material includes a structure based on a system selected from the group consisting of NiCoMnO, NiMnO and CoMnO, and at least one dopant selected from lanthanides, wherein the ceramic material has a negative temperature coefficient of an electrical resistance.

Disclosed herein are embodiments of high Q, temperature stable materials with low dielectric constants. In particular, a two-phase material can form based on the rutile phase of titanium oxide along with a spinel structure of ZnAl.sub.2O.sub.4. This material can have a dielectric constant below 15 which is simultaneously temperature stable.

The composite sintered body includes Al.sub.2O.sub.3, and MgAl.sub.2O.sub.4. The content of Al.sub.2O.sub.3 in the composite sintered body is not less than 95.5% by weight. The average sintered grain size of Al.sub.2O.sub.3 in the composite sintered body is not less than 2 m and not greater than 4 m. The standard deviation of sintered grain size distribution of Al.sub.2O.sub.3 in the composite sintered body is not greater than 0.35. The bulk density of the composite sintered body is not less than 3.94 g/cm.sup.3 and not greater than 3.98 g/cm.sup.3. In the composite sintered body, the ratio of amount of crystal phase of MgAl.sub.2O.sub.4 to that of Al.sub.2O.sub.3 is not less than 0.003 and not greater than 0.01.

A zirconia sintered body contains aluminum, cobalt, and manganese and a remaining portion consisting of yttria-containing zirconia. In an oxide exchange, aluminum content is 5.0 wt % or more and 30.0 wt % or less, cobalt content is 0.1 wt % or more and 2.0 wt % or less, and manganese content is 0.5 wt % or more and 7.0 wt % or less.

A sputtering target comprising a top coat including a composition of lithium cobalt oxide LiyCozOx. x is smaller than or equal to y+z, and the lithium cobalt oxide has an X-Ray diffraction pattern with a peak P2 at 440.2 2-theta. The X-Ray diffraction pattern is measured with an X-Ray diffractometer with CuK1 radiation.

Disclosed is a ceramic material having a formula of Li.sub.wA.sub.xM.sub.2Re.sub.3-yO.sub.z, wherein w is 5-7.5; wherein A is selected from B, Al, Ga, In, Zn, Cd, Y, Sc, Mg, Ca, Sr, Ba, and any combination thereof; wherein x is 0-2; wherein M is selected from Zr, Hf, Nb, Ta, Mo, W, Sn, Ge, Si, Sb, Se, Te, and any combination thereof; wherein Re is selected from lanthanide elements, actinide elements, and any combination thereof; wherein y is 0.01-0.75; wherein z is 10.875-13.125; and wherein the material has a garnet-type or garnet-like crystal structure. The ceramic garnet based material is ionically conducting and can be used as a solid state electrolyte for an electrochemical device such as a battery or supercapacitor.