Impact of Cr 3+ /Mo 6+ /W 6+ Doping on Dipolar Relaxation and AC Conductivity in Li 2 O–Al 2 O 3 –SiO 2 Glasses

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2024-08, Vol.221 (16)
• Main Authors: Vijaya Krishna, Seetepalli, Pavić, Luka, Bafti, Arijeta, Pisk, Jana, Bhadrarao, Dhanisetti, Rao, Yeti Dana, Sekhar, Ayyagari Venkata, Babu, Vandana Chitti, Kumar, Vandana Ravi, Veeraiah, Nalluri
• Format: Article
• Language: English
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.202400243

In this investigation, results of dielectric features of Li 2 O–Al 2 O 3 –SiO 2 (LAS) glass doped with 3.0 mol% of Cr 2 O 3 , MoO 3 , and WO 3 are presented. The investigation spans broad regions of frequency ( ω ) 10 −2 –10 6 Hz and temperature ( T ) 20–240 °C. Initial characterization of the samples by means of optical absorption spectra reveals that Cr ions do persist in Cr 3+ oxidation state, whereas fractions of Mo and W ions do present in Mo 5+ and W 5+ states in addition to predominant presence Mo 6+ and W 6 + ions, respectively. Infrared spectra suggest that Mo 5+ and W 5+ ions involve in modifying the network of the glass and induced structural disorder. Dielectric parameters and also σ ac are observed to be the largest for 40Li 2 O–5Al 2 O 3 –52SiO 2 :3.0 MoO 3 (LASMo) glass followed by 40Li 2 O–5Al 2 O 3 –52SiO 2 :3.0 WO 3 (LASW) and 40Li 2 O–5Al 2 O 3– 52SiO 2 :3.0 Cr 2 O 3 (LASCr) glasses. Analysis of dipolar relaxation phenomena are carried out using Cole–Cole plots. Analysis of the results of σ ac suggests that polaronic conduction due to electron transfer between Mo 5+ ↔ Mo 6+ and W 5+ ↔ W 6+ is prevailed in case of LASMo and LASW glasses and these glasses are predicted to be useful as cathodes, whereas in LASCr glass, ionic conductivity is dominant and is suitable for electrolytes in ionic batteries.