Matsushita Electric Industrial Co., Ltd.

Yukio Terada

Seiichi Nakatani

Eiichi Hirota

Tadashi Kawamata

Hiroshi Kagata

Junichi Kato

Satoru Yuhaku

Tsutomu Nishimura

Yoichiro Yokotani

Toshihiro Mihara

Yasuyuki Baba

A multilayer ceramic capacitor comprises plural ceramic dielectric layers laminated one on another, and at least two internal electrodes separated by the ceramic dielectric layer and alternately terminated at the opposite sides of the laminated ceramic dielectric layers. The ceramic dielectric layers is composed of a complex oxide including a component (A), a component (B) and copper, wherein the component (A), is at least one element selected from the group consisting of Pb, Ca, Sr and Ba, but contains Pb at the least, wherein the component (B) is at least two elements selected from the group consisting of Mg, Ni, Zn, Ti, Ta, Nb and W, the molar ratio of the component (A) to component (B) being not less than 0.985, but not more than 1.110, and wherein the content of said copper in the complex oxide is more than 0.650 wt %, but not more than 2.200 wt % in terms of Cu.sub.2 O. The internal electrodes are composed of copper or an alloy mainly comprising copper.

Multilayer ceramic capacitive element

Multilayered ceramic substrates having Cu electrode patterns in or on ceramic-glass insulating layers which consist essentially of Al.sub.2 O.sub.3, SiO.sub.2, B.sub.2 O.sub.3, Na.sub.2 O, K.sub.2 O, CaO, MgO and PbO. The methods for manufacturing the substrate comprises thermally treating a laminate of alternately superimposing ceramic-glass insulating layers and CuO-based electrode layers of desired patterns in air or in a molecular oxygen-containing atmosphere to eliminate organic binders from the laminates by burning out, reducing the CuO into metallic Cu at low temperatures in an atmosphere containing hydrogen, and firing the thus reduced laminate in an inert gas such as nitrogen. The firing is effected at 850.degree. to 950.degree. C. The multilayered ceramic substrate may also be obtained by forming ceramic-glass insulating layers and CuO-based electrode layers alternately on a sintered ceramic support, followed by the thermal treatment, reduction and firing set forth above.

Multilayered ceramic substrates and method for manufacturing the same

A method for producing, under a low pressure such as an ambient atmospheric pressure, a ferromagnetic chromium oxide having a sufficiently high saturation magnetization and, if necessary, sufficiently high coercive force as well. The main feature of this method is to use H.sub.2 O.sub.2 in conjunction with CrO.sub.3 and, if necessary, Te, Sb or an alkali element as well and to heat them.

Method for producing a ferromagnetic chromium oxide

The present invention provides a ferromagnetic chromium oxide powder having an additive of sulfur incorporated therewith, which powder has a lower curie temperature than that of pure chromium dioxide powder and a high saturation magnetization. Said powder has a composition in weight percent, consisting essentially of 61.90 to 57.22 percent of chromium and 0.0038 to 15.10 percent of sulfur. Moreover, the ferromagnetic chromium oxide powder having a combination of sulfur and further additives selected from tellurium, tin and antimony has a lower Curie temperature than that of pure chromium dioxide together with a high intrinsic coercive force and a high saturation magnetization. The particles of these powders are in a uniform acicular shape and are useful in magnetic recording media, especially for slave tapes in thermo-magnetic duplication.

Process for the preparation of sulfur modified ferromagnetic chromium

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Neyagawa, Japan

Yukio Terada