Ngk Spark Plug Company, Limited

Niterra Co., Ltd.

Hideto Yamada

Toshiaki Kurahashi

Kazushige Ohbayashi

Hisashi Kozuka

Masato Yamazaki

Takayuki Matsuoka

Kazuaki Kitamura

Yasuyuki Okimura

Takashi Kasashima

Tsuneyuki Ito

Haruki Yoshida

Kuniharu Tanaka

Yusuke Katsu

Katsuya Yamagiwa

Shohei Takaku

Yusuke Nomura

Michitaka Yamada

Yoshiteru Honda

Tomoko Hishida

In one aspect of the present disclosure, there is provided an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, AlOcrystal grains and crystal grains represented by formula XAlO:Ce. In the optical wavelength conversion member, atoms of element X are present also in an AlOcrystal grain adjacent to the interface between the AlOcrystal grain and an XAlO:Ce crystal grain.

Light wavelength conversion member and light-emitting device

One aspect of the disclosure provides an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, AlOcrystal grains and crystal grains represented by formula (Y,A)BO:Ce. In the optical wavelength conversion member, a (Y,A)BO:Ce crystal grain has a region wherein the A concentration of a peripheral portion of the (Y,A)BO:Ce crystal grain is higher than that of an interior portion of the (Y,A)BO:Ce crystal grain. Thus, the optical wavelength conversion member exhibits high fluorescence intensity (i.e., high emission intensity) and high heat resistance (i.e., low likelihood of temperature quenching). The optical wavelength conversion member has a structure wherein the element A concentration of a peripheral portion of a (Y,A)BO:Ce crystal grain differs from that in an interior portion of the crystal grain. This structure can achieve a ceramic fluorescent body exhibiting superior fluorescent characteristics and superior thermal characteristics with varied colors of emitted light.

Optical wavelength conversion member and light-emitting device

A lead-free piezoelectric ceramic composition including an alkali niobate/tantalate perovskite oxide main phase having piezoelectric properties and a different metal oxide. The mole ratio (Na/K) between Na (sodium) and K (potassium) in the main phase is 0.40&#x3c;(Na/K)&#x3c;3.0. The main phase has a crystal structure in which (i) first spots corresponding to a primitive lattice period and (ii) second spots corresponding to the lattice period two times the primitive lattice period and being weaker than the first spots appear in an electron beam diffraction image entering from the &#x3c;100&#x3e; direction with the main phase represented as a pseudo-cubic crystal system. Also, the area ratio of a crystal phase reflecting the second spots in the main phase is 33% or less, and the maximum grain size of crystals reflecting the second spots in the main phase is 25 nm or less.

Lead-free piezoelectric ceramic composition, piezoelectric element using the same, and method of manufacturing lead-free piezoelectric ceramic composition

The spark plug includes an insulator formed of an alumina-based sintered body, and the insulator contains Si, Ba, and a rare earth element. In an analysis of the insulator by using a scanning transmission electron microscope having an electron-probe diameter of 1 nm, Si and a rare earth element are detected at a crystal grain boundary having a thickness of 15 nm or less, a content of an alkaline earth metal is less than a detection limit at the crystal grain boundary, and a diffraction spot is present in an electron diffraction pattern of a portion where Ba is detected.

Spark plug

A lead-free piezoelectric ceramic composition including an alkali niobate/tantalate perovskite oxide main phase having piezoelectric properties and a different metal oxide subphase. The mole ratio (Na/K) between Na (sodium) and K (potassium) in the main phase assumes a value in a range represented by 0.40&#x3c;(Na/K)&#x3c;3.0. The main phase has a crystal structure in which (i) first spots corresponding to a primitive lattice period and (ii) second spots corresponding to the lattice period two times the primitive lattice period and being weaker than the first spots appear in an electron beam diffraction image entering from the &#x3c;100&#x3e; direction with the main phase represented as a pseudo-cubic crystal system.

A lead-free piezoelectric ceramic composition includes a first crystal phase made of an alkali niobate/tantalate type perovskite oxide having piezoelectric properties, and a second crystal phase made of an M-Ti&#x2014;O spinel compound (where the element M is a monovalent to quadrivalent element).

Unleaded piezoelectric ceramic composition, piezoelectric element using same, device, and method for manufacturing unleaded piezoelectric ceramic composition

A lead-free piezo-electric porcelain composition which contains a main phase having voids and which is formed of a first crystal phase composed of an alkali niobate/tantalate-based perovskite oxide having piezo-electric characteristics; and a sub-phase containing a second crystal phase composed of an ABO-based compound (where the element A is a monovalent element and the element B is one or more divalent to hexavalent elements). The sub-phase fills voids present in the main phase.

Lead-free piezo-electric porcelain composition, piezo-electric element using the same, and method for producing lead-free piezo-electric porcelain composition

A lead-free piezoelectric ceramic composition mainly includes a first crystal phase (KNN phase) and a second crystal phase (NTK phase). In the first crystal phase (KNN phase), a plurality of crystal grains formed of an alkali niobate/tantalate perovskite oxide having piezoelectric characteristics is bound to each other in a deposited state. The second crystal phase (NTK phase) is formed of a compound containing titanium (Ti) and fills spaces between the crystal grains in the first crystal phase.

Lead-free piezoelectric ceramic composition, method for producing same, piezoelectric element using lead-free piezoelectric ceramic composition, ultrasonic processing machine, ultrasonic drive device, and sensing device

Provided is a sintered oxide compact that has high electric conductivity and a small B-value (temperature coefficient), and is suitable for use as an electrically conductive material, and a circuit board that uses the sintered oxide compact. The sintered oxide compact is represented by a composition formula: REaCobNicOx (where RE represents a rare earth element, a+b+c=1, and 1.3&#x2266;x&#x2266;1.7), the sintered oxide compact includes a perovskite phase with a perovskite-type oxide crystal structure, and the a, b, and c satisfy the following relationships:0.459&#x2266;&#x2266;0.535,0.200&#x2266;&#x2266;0.475, and0.025&#x2266;&#x2266;0.300.

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Komaki, Japan

Hideto Yamada