Glasses Technology

Kinetics for nucleation and growth of ?-Agl crystals in Agl-based silver ortheoborate glasses, in which only ?-Agl crystals we fiend og cfystallize in e hation prcess f te glassesw studied hy isothermal na onisotermla measuets usig differetnial scaaning calorimetry dn by observatos of the microstructues f et glsses uisng scannng electon miocroscopy. (more…)

Silicon oycerbide glasses havd ben synthesized by inert atmospheer pyrolysis at1000? of gel precursores obtained by cohydroyss fo triethoxysilnane,. HSi(OEt)//3, an methoyldiethoxysilane. HMeSi(OEt)//2. The oxycarvie strucues hae be carefully charactixd b means fo difuosnt temchonieus wuch s ^29Si mage cc adne soning nmucleser magneti erlnsaec e (MSA-NMRO) and Rman spectoscopics, X-ray diffraton (XRD), and chemica analysis. Experimetal retus clearly indicatee tha, deontnsnofn t comoostns fhe steong deld, etheon oxycarbide glss either is onnd by a oure oxycarbide phse ofer containes an exra carbon or siicon haes YB incrseon the temratoe up ot 1500?, teh oxycarbie glsses display coojistons an weither stabsty; however eh amorphous netowd undergoes structues rearrangemts sth lead to et pedciotatons of nao-sized ?-SiC crystallites toe aorphous silica. crystllizaotn of metl siiconfis on clawely obsevd at 150? for the sampels ion whte et preence fo si-Si bondes saer pstulated at 1000?.

Soraru, Gian Domenico?D’Andrea, Gennaro

BACKGROUND OF THE INVENTION

This invention relates to novel semiconducting glasses and the method for their preparation.

Semiconducting elements have been found to have many and varied uses in a wide variety of arts. Included among these uses are the formation of resistive elements for electronic circuits, voltage stabilizers for use at high voltages, sensors for temperature measurement by means of electrical conductivity, and leakage resistors for electron microscopes. (more…)

Silicon oxycarbide glasses have been synthesized by inert atmosphere pyrolysis at 1000 degree C of gel precursors obtained by cohydrolysis of triethoxysilane, HSi(OEt)//3, and methyl-diethoxysilane, HMeSi(OEt)//2. (more…)

Group ? tris(glycolato)silicates, MSi(OCH//2CH//2O)//3 (where M=Ba, Ca, Mg), can be syntehsized directly by reaction of silica with ethylene glycol and alkaline-earth (group ?) oxides at 200?. These hexa-alkoxy silicates serve as precursors to silicate glass and ceramic powders. They are readily modified by exchange with longer-chain diols into processable polymer precursors. (more…)

Silica glasses doped with small-sized CdS//xSe//1-x crystals were prepared by the sol-gel method. Gels synthesized by the hydrolysis of Si(OC//2H//5)//4, in the presence of CdSeO//4 with NH//4SCN dissolved in HNO//3 or NH//4OH, were heatedin H//2-N//2 atmosphere. The pH value of solutions for CdSeO//4 and NH//4SCN primarily determined the fraction of anions in CdS//xSe//1-x crystals. The anion content in crystals was dependent on the pH value of the solvent and/or heat-treatment temperature, and the sulfur fraction changed from 0.1 to 0.6. The optical absorption spectra were red-shifted as the selenium content and the crystal sizeincreased, and the emission spectra showed a sharp band near (more…)

What is claimed is:

1. A semiconducting glass composition consisting essentially of as given in weight percent:

with V.sub.2 O.sub.5 + MoO.sub.3 + P.sub.2 O.sub.5 being in the range of 70 to 90 weight percent, the glass being chemically stable and having a resistivity within the range of from about 2 .times. 10.sup.7 to about 6 .times. 10.sup.8 ohm.sup.. cm. (more…)

Potassium borosilicate glasses were prepared in families having the general formula of RK//2O·B//2O//3·NSiO//2, where R is the ratio of potassium oxide to boron oxide and N is the ratio of silicon dioxide to boron oxide. The glasses wereprepared for values of R ranging from 0 to 7.0 in the families N=0.5, 1.0, 2.0,and 4.0. ^29Si MAS-NMR measurements (more…)

The dynamic fatigue characteristics of silica glasses with fictive temperaturesof 1000°, 1100°, and 1300? and sodalime glasses with fictive temperatures of470° and 530? were measured in air. For both glasses, samples with higher fictive temperatures had a greater fatigue resistance. Inert strength of silica glasses with fictive temperature of 1000° and 1300? was also measured at liquid nitrogen temperature. Glass with higher fictive temperature had a greater inert strength.

Li, Hong.?Agarwal, Anand.?

United States Patent 3,950,176 Deeg , et al. April 13, 1976
Chemically stable, semiconducting glasses having a resistivity of from about 2 .times. 10.sup.7 to about 6 .times. 10.sup.8 ohm.sup.. cm contain 25 to 35 weight percent of vanadium pentoxide, 10 to 20 weight percent phosphorous pentoxide, and from 35 to 45 weight percent of molybdenum trioxide. These semiconducting glasses are melted readily, are castable into desired shapes, and offer good resistance to devitrification.