摘要:
A temperature compensating capacitor of monolithic or multilayered configuration comprising a dielectric ceramic body and at least two electrodes buried therein. The ceramic body is composed of a major ingredient expressed by the formula, (SrO).sub.k .multidot.(Zr.sub.1-x Ti.sub.x)O.sub.2, where k and x are numerals in the ranges of 0.8 to 1.3 inclusive and of zero to 0.25 inclusive, respectively. To this major ingredient is added a minor proportion of a mixture of boric oxide, silicon dioxide, and one or more metal oxides selected from among barium oxide, magnesium oxide, zinc oxide, strontium oxide and calcium oxide. For the fabrication of capacitors the mixture of the above major ingredient and additives in finely divided form are formed into moldings of desired shape and size, each with at least two electrodes buried therein. The moldings and electrodes are cosintered in a reductive or neutral atmosphere and then are reheated at a lower temperature in an oxidative atmosphere. The cosintering temperature can be so low that nickel or like base metal can be employed as the electrode material.
摘要:
A monolithic ceramic capacitor having a higher DC breakdown voltage per unit thickness of the dielectric ceramic body than heretofore. The major ingredient of the ceramic is expressed as {(Ba.sub.1-x-y Ca.sub.x Sr.sub.y)O}.sub.k (Ti.sub.1-z Zr.sub.z)O.sub.2, where x, y, z and k are numerals in the ranges specified herein. To this major ingredient is added a minor proportion of a mixture of boric oxide, silicon dioxide, and lithium oxide. The relative proportions of these additives are also specified. For the fabrication of capacitors having dielectric bodies of the above composition, the moldings of the mixture of the major ingredient and additives in the specified proportions are sintered to maturity in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere. The sintering temperature can be so low (1000.degree.-1200.degree. C.) that the moldings can be cosintered with base metal electrodes buried therein.
摘要:
Provided is a vitreous silica crucible for pulling a silicon single crystal, which stably suppresses surface vibration of a silicon melted solution filled therein and has a long life, and a method for manufacturing the same. The vitreous silica crucible for pulling a silicon single crystal includes a peripheral wall portion, a curved portion, and a bottom portion, wherein a plurality of minute concave portions are formed on a certain area of an inner surface of the peripheral wall portion, and a plurality of bubbles are formed on a lower position of the minute concave portions.
摘要:
[Object] To provide a polymer coated ferrite fine particles being possible to control a particle size uniformly while having high aqueous dispersibility and preferred biomolecule immobilization ability and an easy method for preparing the same.[Means Addressing Object] In an aqueous solvent, iron ion is protected by chelating polyacrylic acid and then alkaline is added. Thereafter, a reaction system is heated under pressurized condition to produce simultaneous precipitation of the ferrite fine particles and coating thereof. As the result, the polymer coated ferrite fine particles having uniform particle size may be prepared in one step with excellent reproducibility. The polymer coated ferrite fine particles of the present invention has high water dispersibility and has preferred biomolecule immobilization performance by carboxyl groups coming from the polyacrylic acid.
摘要:
The present invention provides a vitreous silica crucible which can restrain deterioration of crystallinity of a silicon ingot in multi-pulling. Provided is a vitreous silica crucible for pulling a silicon single crystal, the crucible has a wall having, from an inner surface toward an outer surface of the crucible, a synthetic vitreous silica layer, a natural vitreous silica layer, an impurity-containing vitreous silica layer and a natural vitreous silica layer.
摘要:
The present invention provides a method of evaluating silica powder which, enables precise prediction of easiness of crystallization of a vitreous silica crucible. According to the present invention, provided is a method of evaluating silica powder including a sample preparation process for preparing a vitrified sample by fusing silica powder at a fusing temperature of 1700 to 1900 deg. C., followed by cooling; a sample heat treatment process for retaining the sample for 30 minutes or more at a temperature of 1400 to 1750 deg. C., followed by cooling; and a sample evaluation process for evaluating a state of opacification of the sample after the sample heat treatment process.
摘要:
Provided is a vitreous silica crucible which can suppress inward sagging and buckling of the sidewall effectively even when time for pulling silicon ingots is extremely long. According to the present invention, provided is a vitreous silica crucible for pulling a silicon single crystal, wherein the crucible has a wall comprising, from an inner surface toward an outer surface of the crucible, a transparent vitreous silica layer having a bubble content rate of less than 0.5%, a bubble-containing vitreous silica layer having a bubble content rate of 1% or more and less than 50%, a semi-transparent vitreous silica layer having a bubble content rate of 0.5% or more and less than 1.0% and having an OH group concentration of 35 ppm or more and less than 300 ppm.
摘要:
The present invention provides a vitreous silica crucible which can suppress the sidewall lowering of the crucible under high temperature during pulling a silicon single crystal, and a method of manufacturing such a vitreous silica crucible. The vitreous silica crucible 10 includes an opaque vitreous silica layer 11 provided on the outer surface side of the crucible and containing numerous bubbles, and a transparent vitreous silica layer 12 provided on the inner surface side. The opaque vitreous silica layer 11 includes a first opaque vitreous silica portion 11a provided on the crucible upper portion, and a second opaque vitreous silica portion 11b provided on the crucible lower portion. The specific gravity of the second opaque vitreous silica portion 11b is 1.7 to 2.1, and the specific gravity of the first opaque vitreous silica portion 11a is 1.4 to 1.8, and smaller than that of the second opaque vitreous silica portion. The particle size distribution of the material silica powder for the first opaque vitreous silica portion 11a is wider than that of the second opaque vitreous silica portion 11b, and the material silica powder for the first opaque vitreous silica portion 11a includes more fine powder than that for the second opaque vitreous silica portion 11b.
摘要:
In order to provide a vitreous silica crucible which does not employ a crystallization accelerator but is difficult to deform during its use even under high temperature, and is easily manufactured, there is provided a vitreous silica crucible for pulling single-crystal silicon wherein the outer surface layer is formed of a bubble-containing vitreous silica layer, the inner surface layer is formed of a vitreous silica layer whose bubbles are invisible to the naked eye, a surface of the outer surface layer includes an unmelted or half-melted silica layer (abbreviated as a half-melted silica layer), and the center line average roughness (Ra) of the half-melted silica layer is 50 to 200 μm, also preferably, and the thickness of the half-melted silica layer is 0.5 to 2.0 mm.
摘要:
Provided are an apparatus and a method for manufacturing a vitreous silica crucible, which enable accurate measurement of a fume generation amount, prevention of deterioration of an inner surface property, and real-time control of a raw material melting state. Provided is an apparatus for manufacturing a vitreous silica crucible 50 by supplying silica powder into a mold 10 to form a silica powder layer 11, and heating and melting the silica powder layer 11 by arc discharge. The apparatus includes the mold 10 for defining an outer shape of a vitreous silica crucible, an arc discharge unit having a plurality of carbon electrodes 13 and a power-supply unit 40, and a fume-amount measurement unit 30 for detecting an amount of fumes 80 generated in the mold 10.