Obtaining and conductive properties of a vanadate-borate-phosphate glass

Abstract

Vanadate glasses exhibit semiconducting property at certain temperatures. This work demonstrates the conductivity of the composition 45V₂O₅-25B₂O₃-30P₂O₅, which is a new glass in the vanadium-boron-phosphorus ternary system that expands the glass forming area reported in literature data. The glass was obtained through a classical melt-quenching technique. The structural composition of the obtained glass was revealed with Raman spectroscopy and the amorphous characteristic has been highlighted with X-ray diffraction. The characteristic temperatures and the thermal expansion coefficient were determined by dilatometry. Based on the experimental measurements of electrical resistance, mathematical calculations were performed, resulting in a conductivity of 2.04·10^-6 S/cm at 125 °C, and an activation energy of 42.91 kJ/mol for this glass. Impedance spectroscopy in DC and AC at 100 V and 100 Hz to 2 MHz, respectively, showed a lower activation energy of about 0.166 eV and transition temperatures of 24 °C and 11 °C, respectively. These results were compared with those from the literature considering the temperatures at which the reported conductivities were measured. This glass has potential applications in electronic devices and temperature sensors.

Figure 1

The obtained samples after glass casting in (a) prismatic and (b) disc shapes.

Figure 2

Diagram for V₂O₅–B₂O₃–P₂O₅ system ^,,,,,,.

Figure 3

The XRD diffractogram for 45V₂O₅–25B₂O₃–30P₂O₅ glass.

Figure 4

The 45V₂O₅–25B₂O₃–30P₂O₅ glass dilatometry graph containing the characteristic temperatures, strain temperature (T_IR); glass transition temperature (Tg); annealing temperature (T_SR); dilatometric softening temperature (T_D) and the expansion coefficient T. Alpha (1/K).

Figure 5

The Raman spectra for 45V₂O₅–25B₂O₃–30P₂O₅ glass.

Figure 6

Logarithmic conductivity versus 10³/T for the 45V₂O₅–25B₂O₃–30P₂O₅ glass.

Figure 7

(a) The conductivity variation with temperature, in DC; (b) Arhhenius plot of logarithmic conductivity to 10³/T.

Figure 8

(a) The real part of dielectric permittivity variation with frequency and temperature; (b) The imaginary part of dielectric permittivity variation with frequency and temperature. The temperature increases from blue to red in figure.

Figure 9

The dielectric loss versus frequency and temperature. The temperature increases from green to red.

Figure 10

(a) Conductivity variation with frequency and temperature. Temperature increases from blue to red; (b) Conductivity variation with temperature at several frequencies; (c) Arrhenius plot of logarithmic conductivity with 10³/T.