Abstract: This invention provides a method for producing an oxide superconductor which has a uniform texture and is markedly high in sintered density and current density.The method involves the formation of intermediate products from the starting materials. The intermediate products are then used to form the final product. Specifically, to form an oxide superconducting material having a compositional formulaYBa.sub.2 CU.sub.3 O.sub.7-8,where 8 is more than zero but less than 0.5, the method of the invention includes forming a first intermediate product of Y.sub.2 CU.sub.2 O.sub.5, forming a second intermediate product of BaCuO.sub.2, mixing the first and second intermediate products, and sintering the intermediate product mixture to form the oxide superconducting material.

Abstract: A glow plug for a diesel engine includes a U-shaped ceramic heater of SIALON supported by a hollow metallic holder. The heater has a U-shaped heating portion projecting from one end of the holder and is supported therein by a pair of parallel ceramic lead portions of a thicknesses greater than the heating portion. One lead portion is electrically connected to the interior of the holder and the other lead portion is electrically insulated from the holder and electrically connected to an external connecting terminal extending into the other end of the holder. The lead portions are spaced from each other to define a slit therebetween open to the interior of the holder. A sintered ceramic sheet of SIALON integrally seals the slit against entry of combustion gases into the interior of the holder.

Abstract: There is disclosed glow plug for a diesel engine provided with an elongated ceramic heater retained by an opening end of a hollow holder with one end of said ceramic heater being projected toward the outside. The ceramic heater comprises an insulating tubular section of an insulating ceramic material, and a heating body as a continuous conductive section formed so as to cover the outer peripheral portion, the outermost portion and the hollow portion of the insulating tubular section with a conductive ceramic material, the heating body being formed in a manner that the thickness of at least the outer peripheral portion of the insulating tubular member in the vicinity of said one end of the ceramic heater is thinner than that of other portions thereof. The insulating tubular section and the heating body constituting the ceramic heater are integrally formed with the ceramic material which can select insulating property and conductive property by adjusting an amount of titanium nitride added into .beta.