Material characteristics of WO3/Bi2O3 substitution on the thermal, structural, and electrical properties of lithium calcium borate glasses
A.A. Ali, Ahlam M. Fathi, S. Ibrahim
Abstract
Abstract Glasses belonging to the x WO 3 -(30- x ) Bi 2 O 3 –15Li 2 O–15CaO–40B 2 O 3 (0 ≤ x ≤ 10) have been obtained by melt-quenching technique. With increasing the concentration of WO 3 , an increase in the measured glass transition temperature $${T}_{\mathrm{g}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>T</mml:mi> <mml:mi>g</mml:mi> </mml:msub> </mml:math> and crystallization temperature $${T}_{\mathrm{c}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>T</mml:mi> <mml:mi>c</mml:mi> </mml:msub> </mml:math> are observed, while the values of the thermal expansion coefficient decrease. Due to the unpaired pentavalent ions, the electron spin resonance spectra of glasses doped with $${\mathrm{WO}}_{3}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>WO</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:math> them show unique signals. The results of Raman spectra show that the glass network is mainly constituted by [ $${\mathrm{BiO}}_{6}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>BiO</mml:mi> <mml:mn>6</mml:mn> </mml:msub> </mml:math> ], [ $${\mathrm{BO}}_{3}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>BO</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:math> ], [ $${\mathrm{BO}}_{4}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>BO</mml:mi> <mml:mn>4</mml:mn> </mml:msub> </mml:math> ], and [ $${\mathrm{WO}}_{4}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>WO</mml:mi> <mml:mn>4</mml:mn> </mml:msub> </mml:math> ] basic structural units. The activation energies for all studied samples were observed to range from 0.02 to 0.08 eV, and the dielectric constant and the conductivities of the investigated glasses increased with increasing temperature. The electrical behavior of the prepared samples revealed their semiconducting character. The prepared samples are being investigated as potential semiconductor material candidates for use in electronic devices.