Transport properties of zinc-bismuth oxide glasses

28-32<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Zinc-bismuth oxide glasses of 10-25 mol% of zinc oxide are prepared having thickness between 0.35-0.42 cm and diameter 0.60-0.95 cm. Physical properties such as density (d), molar volume <span style="font-size:11.0pt; line-height:115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;="" mso-fareast-font-family:"times="" new="" roman";mso-fareast-theme-font:minor-fareast;="" mso-hansi-theme-font:minor-latin;mso-bidi-font-family:arial;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa;mso-bidi-font-style:="" italic"="">(V),<span style="font-size:11.0pt;line-height: 115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;="" mso-fareast-font-family:"times="" new="" roman";mso-fareast-theme-font:minor-fareast;="" mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"=""> hopping distance <span style="font-size:11.0pt;line-height:115%;font-family: " calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa;mso-bidi-font-style:italic"="">(R), number of ions per cc (N) and polaron radius <span style="mso-bidi-font-style: italic">(rp) are also reported. Polaron radius is found around 1.85 <span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-theme-font:minor-latin;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">Å<span style="font-size:11.0pt; line-height:115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;="" mso-fareast-font-family:"times="" new="" roman";mso-fareast-theme-font:minor-fareast;="" mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"=""> which shows formation of small polarons. Measurements of de electrical conductivity are reported in the temperature range 443-573K. - Log σ<span style="font-size:11.0pt; line-height:115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;="" mso-fareast-font-family:"times="" new="" roman";mso-fareast-theme-font:minor-fareast;="" mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"=""> versus 1/T and –log µ versus 1/T plots exhibited linearity. Hopping condition given by Holstein was applied. Polaron band-width (J) satisfies the inequality which shows adiabatic hopping conduction. The density of Fermi level and the density of localized states are found to be close to each other.</span

Effect of Past Electric Field on Transport Properties of 8Ov<Sub>2</Sub>O<Sub>5</Sub>-2Op<Sub>2</Sub>O<Sub>5</Sub> Semiconducting Glass

The effect of past electric field on transport properties such as dc-conductivity, activation energy etc. of 8Ov2O5-2Op2O5 semiconducting glass has been considered. The various parameters N,rp,N (EF) etc. Are calculated from Mou T1/4 analysis, and the results are discussed on the basis of the polaron model

<span style="font-size:11.0pt;line-height:115%; font-family:"Calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family: "Times New Roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font: minor-latin;mso-bidi-font-family:Arial;mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA">Thermal conductivity of V₂O₅-P₂O₅ glasses</span>

291-296<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">The thermal conductivity of V2O5-P2O5 glass system has been experimentally determined in the temperature range 303-422 K. The data covered the glass composition range from 60 to 80 mol% of V2O5. It has been observed that the thermal conductivity increases linearly with temperature. The results obtained confirmed that the major contribution to the thermal conductivity of this glass system is due to lattice vibrations. The values of density, molar volume, lattice thermal conductivity (λL) band gap energy, melting temperature, electronic (λe) and bipolar component of thermal conductivity (λbp) are also reported.</span

Hopping Conduction Mechanism in Amorphous CuO-Bi2\text{}_{2}O3\text{}_{3} Pellets

The transport properties of CuO-Bi$\text{}_{2}$O$\text{}_{3}$ pellets (pressed at room temperature 303 K) like dc electrical conductivity etc. are measured. The activation energy, dielectric constant etc. are reported. The hopping conduction is examined. Non-adiabatic hopping conduction is observed. The plot of -log σ versus 1/T is found to be linear. Activation energy of pellets containing CuO (80, 70, 60 mol%) shows electronic conduction while the pellet containing CuO (50 mol%) shows ionic conduction. The effect of content of CuO (mol%) and frequency on dielectric constant is also studied. The variation of dielectric constant with CuO (mol%) shows zigzag nature and may be due to the relaxation effects

<span style="font-size:11.0pt;line-height:115%; font-family:"Calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family: "Times New Roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font: minor-latin;mso-bidi-font-family:Arial;mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA">Effect of pellet pressing temperature on transport properties of amorphous CuO-Bi₂O₃ pellets</span>

231-235<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">The results of transport properties of CuO-Bi2O3 pellets pressed at different temperatures are reported. The data of electrical properties such as dc-electrical conductivity, dielectric constant and activation energy are discussed. Similarities between CuO-Bi2O3 pellets and oxide glasses are emphasized. New results of pellet pressing temperature are reported. The hopping conduction phenomenon in three sets of pellets is discussed. All the three pellets exhibited non-adiabatic electronic conduction. The results of dc-conductivity are discussed on the basis of growing of small crystallities in the pellets.</span

<span style="font-size:11.0pt;line-height:115%; font-family:"Calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family: "Times New Roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font: minor-latin;mso-bidi-font-family:"Times New Roman";mso-ansi-language:EN-US; mso-fareast-language:EN-US;mso-bidi-language:AR-SA">Transport properties of amorphous CuO-Bi₂O₃ semiconducting pellets</span>

33-37<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The results of measurement of de-electrical conductivity and activation energy have been reported for four different composition of CuO-Bi2O3 glass powder pellets pressed at 50°C in the temperature range of 300 - 493 K. A plot of -log σ<span style="font-size:11.0pt; line-height:115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;="" mso-fareast-font-family:"times="" new="" roman";mso-fareast-theme-font:minor-fareast;="" mso-hansi-theme-font:minor-latin;mso-bidi-font-family:arial;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"=""> versus 1/T shows two different regions of conduction suggesting two types of conduction mechanisms switching from one type to another occurring at Rnee temperature. The de-conductivity increases with increase in temperature of the sample and also with increase of mol% of CuO. Activation energy calculated for both regions (LTR and HTR) is below 1 eV, thus the electrical conduction is electronic. Activation energy decreases with increase of mol% of CuO. Non-adiabatic hopping conduction was observed in the sample. A plot of dielectric constant versus log of frequency shows zig-zag nature. Dielectric constant decreases with increase in mol% of CuO.</span