ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13591.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

Results are presented in which BaTiO2single crystals with various impurity additions were grown and their effect on crystal quality, switching behavior, and electrical solid‐state properties was investigate

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13592.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

A large piezoresistance response to hydrostatic pressure is reported for a series of ceramic compositions in the system barium strontium lanthanum titanate (Ba, Sr, La)TiO2. This property appears to be closely associated with the Curie region (cubic‐tetragonal phase transition) and the phenomenon of a positive temperature coefficient of resistance for these same compositions. The piezoresistance coefficient, similar to the temperature coefficient of resistance, is positive in the Curie region, and is found to range up to the order of 700 X 10−12sq. cm. per dyne. Consistent with the observed piezoresistance effect, a positive piezocapacitive effect, ranging up to the order of 700 x 10−12sq. cm. per dyne, is observed in these compositions in the absence of the lanthanum impurity which produces semiconduction. It is suggested that these materials may be of interest in pressure‐sensitive devices such as acoustic transducers and pressure‐sensing elements and in techniques for measuring force and dis

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13593.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

Some borate glasses, with sag points of 350° to 500°C., of high specific resistance and low power factor have been prepared. The power factor of the glasses has been measured to 250° C., and the resistivity has been measured up to temperatures approaching the transformation region. Borate glasses have higher resistivities and power factors than phosphate glasses. An increase in sag point of lead borate glasses by substitution of PbO with BaO, Al2O3, or SiO2improves their dielectric properties. Depending on the type of glass, the dielectric constant varies linearly with the density of the gla

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13594.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

The chemical attack of a soda‐lime glass by the combined action of ethylene diamine tetraacetic acid and ortho‐dihydroxy benzene (catechol) in dilute aqueous solution is reported u a function of pH. A pronounced maximum occurs in the rate of attack at a pH value determined by the anionic species present. The effects are ascribed to the chelation of the protective cations A13+, Ca2+, and Mg2+by ethylene diamine tetraacetic acid and to the chelation of Si4+by catec

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13595.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

An empirical equation form, approximating the apparent dependence of the strength of brittle polycrystalline specimens on the combined effect of porosity and grain size, has been developed from concepts and data in the literature. The form is shown to be applicable to data for thoria and chromium carbide specimens.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13596.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

High stresses arise in sintered β‐eucryptite (Li2O. Al2O2‐2SiO2) during cooling from the firing temperature because of its extreme anisotropy of thermal expansion. These stresses cause extensive fracturing of the crystals, resulting in abnormally low mechanical property values at room temperature. During reheating, many fractures recombine, causing increase in strength and in elastic modulus with increasing temperature. Beta‐eucryptite creeps under load at room temperature because of additional fracturing and the propagation of fractures. Equations are presented for calculating internal stresses in sintered single‐phase aggregates of anisotropic

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13597.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

The formation of alpha aluminum oxide micro‐crystals on objects heated in resistance furnaces with an aluminum oxide tube and a hydrogen atmosphere is reported. It is deduced that the crystals grow from the vapor produced by the reaction between the aluminum oxide furnace tube and the hydrogen atmosphere. Evidence for growth by the screw dislocation mechanism is presente

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13598.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

Oxygen ion mobility in the cubic fluorite‐structure phase having the composition Zr0.85Ca0.15O1.85has been directly determined by exchange measurements employing the stable isotope O18and mass spectrometer analysis. Measurements of electrical conductivity have been carried out as a function of both temperature and oxygen pressure. Results indicate that the conductivity is wholly ionic with a transfer number near unity for the oxygen io

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13599.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

A study has been made of the binary system Fe2O2‐TiO2by solid‐state reactions under dry and hydrothermal conditions. Under dry conditions only one binary compound, pseudobrookite (Fe2O3‐TiO2), was formed and no evidence of solid solution on either side of this compound at temperatures up to 1200°C. was obtained. The system under these conditions is a simple binary with a single binary compound. Under hydrothermal conditions of 300° C. and 1200 Ib. per sq. in. the system is apparently also binary, with a single unstable compound closely resembling, if not identical with, the naturally occurring mineral arizonite (ferric metatitanate, Fe2(

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1959.tb13600.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY