Tellurite containing vanadate (50−x)V2O5–xBi2O3–50TeO2 glasses with different bismuth (x=0, 5, 10, 15, 20 and 25 wt%) contents have been prepared by rapid quenching method. Ultrasonic velocities (both longitudinal and shear) and attenuation (for longitudinal waves only) measurements have been made using a transducer operated at the fundamental frequency of 5 MHz in the temperature range from 150 to 480 K. The elastic moduli, Debye temperature, and Poisson’s ratio have been obtained both as a function of temperature and Bi2O3 content. The room temperature study on ultrasonic velocities, attenuation, elastic moduli, Poisson’s ratio, Debye temperature and glass transition temperature show the absence of any anomalies with addition of Bi2O3 content. The observed results confirm that the addition of Bi2O3 modifier changes the rigid formula character of TeO2 to a matrix of regular TeO3 and ionic behaviour bonds (NBOs). A monotonic decrease in velocities and elastic moduli, and an increase in attenuation and acoustic loss as a function of temperature in all the glass samples reveal the loose packing structure, which is attributed to the instability of TeO4 trigonal bipyramid units in the network as temperature increases. It is also inferred that the glasses with low Bi2O3 content are more stable than with high Bi2O3 content.

Characterisation of semiconducting V2O5–Bi2O3–TeO2 glasses through ultrasonic measurements

Highly-conducting indiumtin-oxide transparent films fabricated by spray CVD using ethanol solution of indium (III) chloride and tin (II) chloride

Semiconductive oxide glasses in the system V2O5–MnO–TeO2 were prepared, and the mechanism of d.c. conduction was studied. The Seebeck coefficient measurements at temperatures from 375–475 K indicated the glasses to be n-type semiconducting. The d.c. conductivity ranged from 5×10−5 to 1.9×10−6 S cm−1 at 405 K for V2O5=60 mol% and MnO=0–20 mol%, and decreased with increasing MnO content. The conduction was confirmed to obey the adiabatic small polaron hopping model, and was due to mainly hopping between V-ions in the glasses. The polaron band width J was estimated to be J=0.10–0.20 eV. The electron–phonon interaction coefficient γp was very large (21–26). The hopping mobility evaluated as 2.3×10−7–2.7×10−6 cm2 V−1 s−1 increased with increasing V2O5 content. The estimated carrier concentration was the order of 1019 cm−3. The principal factor determining conductivity was the polaron hopping mobility in these glasses. © 1998 Chapman & Hall

D.c. conductivity of V2O5–MnO–TeO2 glasses

The dc conductivity of MoO3-TeO2 glasses prepared by melt quenching has been investigated in the temperature range 323-473 K. Seebeck coefficient measurements indicate the glasses to be n-type. The conductivity increases with increase of MoO3 content and at 418 K varies from about 6×10-6 to 1×10-8 S cm-1. The conduction is attributed to non-adiabatic hopping of small polarons due to the different valence states, Mo5+ and Mo6+, the existence of which was confirmed from x-ray photoelectron spectroscopy analysis of the glasses. Fourier transform infrared spectroscopic studies show the presence of MoO6, MoO4, TeO3 and TeO4 structural units in the glasses.

https://iopscience.iop.org/article/10.1088/0022-3727/34/4/303/pdf

Structural and electrical properties of MoO3-TeO2 glasses

Fabrication of thin films of ITO by aerosol CVD

Thermal decomposition of basic copper carbonate, CuCO3 · Cu(OH)2 · H2O, in carbon dioxide atmosphere (0–50 atm)

Fe2O3-Sb2O3-TeO2 glasses were prepared by the pressquenching method and their do conductivities were measured. The glass formation region was found to be 0≤Fe2O3≤15mot%, 0≤Sb2O3≤18mol%, and 78≤TeO2<100mol%. Seebeck coefficient measurements showed that these glasses were n-type semiconductors. The glasses gave conductivities σ ranging from 1.62×10-6 to 1.86×10-7 S·cm-1 at 473K. The dc conductivity increased with an increase in Fe2O3 content. Evaluated carrier mobility and concentration ranged from 7.5×10-10 to 5.3×10-3cm2·V-1·s-1 and from 1.5×1021 to 1.9×1015cm-3 at 473K, respectively. The conduction of these glasses was due to non-adiabatic small polaron hopping.

https://www.jstage.jst.go.jp/article/jcersj1988/103/1193/103_1193_32/_pdf

Electrical Conduction of Glasses in the System Fe2O3-Sb2O3-TeO2

Fe2O3-PbO-Bi2O3 glasses were prepared by the press-quenching method and their dc conductivities in the temperature range 373-573K were measured. The glass formation region was found to be Fe2O3=0-30mol%, PbO=0-40mol%, Bi2O3=0-100mol%. The Seebeck coefficients showed these glasses to be p-type semiconductors. The glasses had conductivities, σ, ranging from 2.82×10-6S·cm-1 to 2.69×10-4S·cm-1 at 573K for Fe2O3=20-30mol%. The dc conductivity increased with increasing Fe2O3 content. Electrical conduction was confirmed to be due to nonadiabatic small polaron hopping, and the conductivity was primarily determined by the hopping mobility. The polaron band width, J, ranged from 0.03 to 0.28eV depending on the Fe-Fe spacing. The IR absorption spectra suggested that the quenched glasses contained FeO4 tetrahedra and BiO6 octahedra.

Electrical conductivity of Fe2O3-PbO-Bi2O3 glasses

Sb2O3-SrO-V2O5 glasses were prepared by a cast quenching method and their electrical conductivity was investigated, together with that of crystallized ones from these glasses. The glass forming region was V2O5 65-95, SrO 5-35, Sb2O3 0-15 (mol%) with Tg =280•‹-282•Ž. The electrical conductivity was in the range from 7•~10-7S•Ecm-1 to 10-5S•Ecm-1 at 300K ex hibiting small polaron hopping conduction of elec trons. At temperatures lower than room temperature, another mechanism of conduction superposed on that hopping conduction. These glasses and crystallized ones were confirmed to be n-type semiconductors by Seebeck constant measurements. The crystallized glasses gave higher conductivities from 3.3•~10-4S •E cm-1 to 1.8•~10-2S•Ecm-1 at 300K. The relationships between conductivity and temperature showed that the conduction was due to variable range hopping in a tem perature range from 100K to 300K. Mott's parameter for variable range hopping for these crystallized glass es were evaluated, their disorder energy at low temper ature was estimated to be of the order of 0.09-0.11eV. Discussions led to the conclusion that the conduction of these crystallized glasses was interpreted to be a mixed conduction of small polaron hopping and varia ble range hopping at temperature between 100K and 300K.

https://www.jstage.jst.go.jp/article/jcersj1988/100/1168/100_1168_1398/_pdf

Toru Hirayama

Papers

Thermal decomposition of basic copper carbonate, CuCO3 · Cu(OH)2 · H2O, in carbon dioxide atmosphere (0–50 atm)

Electrical Conduction of Glasses in the System Fe2O3-Sb2O3-TeO2

Electrical conductivity of Fe2O3-PbO-Bi2O3 glasses

Electrical Poperties of Sb2O3-SrO-V2O5 Glasses and Crystallized Ones

Influence of the self-generated and controlled atmosphere on the thermal decomposition of basic nickel carbonate, NiCO3·2Ni(OH)2·4H2O