Higher Fe{sup 2+}/total Fe ratio in iron doped phosphate glass melted by microwave heating

Journal Article · Sun Mar 15 04:00:00 EDT 2015 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2014.11.052· OSTI ID:22420836

Sinha, Prasanta K. ^[1]; Das, Dipankar ^[2]; Guha, Chandan ^[3]; Sen, Ranjan ^[1]

---

1. CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India)
2. UGC-DAE Consortium for Scientific Research, Kolkata 700098 (India)
3. Department of Chemical Engineering, Jadavpur University, Kolkata 700032 (India)

Highlights: • Iron doped phosphate glasses prepared using microwave heating and conventional heating under air and reducing atmosphere. • Presence of iron predominantly in the ferrous oxidation state in all the glasses. • Significant concentrations of iron in the ferrous oxidation state on both octahedral and tetrahedral sites in all the glasses. • Ratio of Fe{sup 2+} with total iron is found higher in microwave prepared glasses in comparison to conventional prepared glasses. - Abstract: Iron doped phosphate glasses containing P{sub 2}O{sub 5}–MgO–ZnO–B{sub 2}O{sub 3}–Al{sub 2}O{sub 3} were melted using conventional resistance heating and microwave heating in air and under reducing atmosphere. All the glasses were characterised by UV–Vis–NIR spectroscopy, Mössbauer spectroscopy, thermogravimetric analysis and wet colorimetry analysis. Mössbauer spectroscopy revealed presence of iron predominantly in the ferrous oxidation state on two different sites in all the glasses. The intensity of the ferrous absorption peaks in UV–Vis–NIR spectrum was found to be more in glasses prepared using microwave radiation compared to the glasses prepared in a resistance heating furnace. Thermogravimetric analysis showed increasing weight gain on heating under oxygen atmosphere for glass corroborating higher ratio of FeO/(FeO + Fe{sub 2}O{sub 3}) in glass melted by direct microwave heating. Wet chemical analysis also substantiated the finding of higher ratio Fe{sup +2}/ΣFe in microwave melted glasses. It was found that iron redox ratio was highest in the glasses prepared in a microwave furnace under reducing atmosphere.

• OSTI ID: 22420836
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Vol. 63; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
ALUMINIUM OXIDES
BORON OXIDES
CERAMIC MELTERS
DOPED MATERIALS
ELECTRIC HEATING
IRON
IRON IONS
IRON OXIDES
MAGNESIUM OXIDES
MICROWAVE HEATING
MICROWAVE RADIATION
MOESSBAUER EFFECT
OPTICAL PROPERTIES
PHOSPHATE GLASS
PHOSPHORUS OXIDES
THERMAL GRAVIMETRIC ANALYSIS
ZINC OXIDES