Nippon Electric Co., Ltd.

Nec Corporation

Ohizumi Mfg. Co., Ltd.

Nobuaki Shohata

Tomeji Ohno

Kazuaki Utsumi

Koichi Saito

Hisanao Tsuge

Takeshi Obata

Shigeru Ikeda

Toshiyasu Hishii

Tokuo Takeuchi

Toshio Takaba

Ryuji Igarashi

Takaki Fukushima

Jyun-Ichiro Yoshida

A magnetic oxide represented by A.sub.1-x A'.sub.x Mn.sub.1-y M.sub.y O.sub.z, where: A is at least one element selected from the group consisting of lanthanoid, Y and Bi; A' is at least one element selected from the group consisting of alkaline earth metals and Pb; M is at least one element selected from the group consisting of Ni and Cu; 0&lt;x, y.ltoreq.0.5; and 2.5.ltoreq.z.ltoreq.3.5.

Magnetic oxide having a large magnetoresistance effect at room

For use in a gas sensor, an integrated gas sensitive unit comprises, on a single principal surface, a gas sensitive semiconductor element and a first resistor member connected to the element in series for deriving an electrical signal from the element. Both of the element and the first resistor member may be formed by the thick-film integration technique. A heating wire may be attached to the back surface opposite to the principal surface. A combination of secnd and third resistor members may be electrically connected to the series connection in parallel with the second and the third resistor members brought into electrical contact with the element and the first resistor member, respectively, to form a bridge circuit. The combination may be formed on the principal surface together with the series connection or separated from the series connection. Preferably, the first or the second resistor member has the same temperature dependency as the element when the heating wire is attached to the bridge circuit.

Integrated gas sensitive unit comprising a gas sensitive semiconductor

A 'varistor' or voltage-dependent nonlinear resistor employs a ceramic base body having a voltage-dependent nonlinearity. First and second lead-out electrode layers are formed on first and second external surfaces, respectively, of the ceramic base body. Within and enclosed by the ceramic base body, a plurality of internal electrodes extend in parallel with each other and connect to the external lead-out electrodes. Also, the invention provides a method of manufacturing the voltage-dependent nonlinear resistor comprising the steps of forming a plurality of raw sheets of material, each having the desired voltage-dependent nonlinearity characteristics, after sintering. Internal electrodes of conducting material are printed on each of these sheets. The sheets are then laminated, cut and formed with external electrodes connecting the internal electrode to each other.

Voltage dependent nonlinear resistor

Nonohmic ZnO ceramics including the following additives have the voltage nonlinear exponent .alpha. of 30 or more, the dielectric constant .epsilon. of about 1000 or less, the loss factor (tan .delta.) of less than 10%, and small variations caused in the breakdown voltage V.sub.i by load and large current pulses. The additives listed by molecular formulae are given in % by mol. The glass components are given for Nos. 1 through 4 in % by weight, symbols of elements being representative of borosilicate lead and/or zinc glass.

Nonohmic ZnO ceramics including Bi.sub.2 O.sub.3, CoO, MnO, Sb.sub.2 O.sub.

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Tokyo, Japan

Nobuaki Shohata