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Agricultural wastes as a resource of raw materials for developing low-dielectric glass-ceramics.

Danewalia SS, Sharma G, Thakur S, Singh K - Sci Rep (2016)

Bottom Line: Sugarcane leaves ash exhibits higher content of alkali metal oxides than rice husk ash, which reduces the melting point of the components due to eutectic reactions.The presence of less ordered augite phase enhances the dielectric permittivity as compared to cristobalite and tridymite phases.The glass-ceramics developed with adequately devitrified phases can be used in microelectronic devices and other dielectric applications.

View Article: PubMed Central - PubMed

Affiliation: School of Physics and Materials Science, Thapar University, Patiala-147004, India.

ABSTRACT
Agricultural waste ashes are used as resource materials to synthesize new glass and glass-ceramics. The as-prepared materials are characterized using various techniques for their structural and dielectric properties to check their suitability in microelectronic applications. Sugarcane leaves ash exhibits higher content of alkali metal oxides than rice husk ash, which reduces the melting point of the components due to eutectic reactions. The addition of sugarcane leaves ash in rice husk ash promotes the glass formation. Additionally, it prevents the cristobalite phase formation. These materials are inherently porous, which is responsible for low dielectric permittivity i.e. 9 to 40. The presence of less ordered augite phase enhances the dielectric permittivity as compared to cristobalite and tridymite phases. The present glass-ceramics exhibit lower losses than similar materials synthesized using conventional minerals. The dielectric permittivity is independent to a wide range of temperature and frequency. The glass-ceramics developed with adequately devitrified phases can be used in microelectronic devices and other dielectric applications.

No MeSH data available.


Related in: MedlinePlus

Raman spectra of the quenched samples derived from agricultural waste ash.
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f4: Raman spectra of the quenched samples derived from agricultural waste ash.

Mentions: Figure 4 shows the Raman spectra for present glasses and glass-ceramics. Raman spectra mainly show three bands for R-100 and R-75 glass-ceramics i.e. ~114, 232 and 420 cm−1, respectively. On the other hand, R-50 glass shows a very feeble band ~148 cm−1. In addition to this, it is observed that the spectra of R-100 and R-75 exhibit higher band intensity at higher wavenumbers. It can be related to either thermal background or to the possible luminescence from the material31. The bands exhibit slight variation due to formation of NBOs and change in structural units32. In general, Raman bands in silica and silicate glasses fall in three regions namely, near 1060 and 1200 cm−1 with weak intensity, ~800 cm−1 with medium intensity and ~430 cm−1 with maximum intensity33. Disturbed short range order due to glass modifier ions may suppress the intensity of Raman bands. Hence, the low intensity bands disappeared and only high intensity bands could be visible in the present samples. The bands at ~114, 232 and 420 cm−1 are attributed to symmetric stretching of Si-O-Si bond in cristobalite (SiO2) phase3435. These Raman bands are asymmetric as indicated by the deviation from pure Gaussian curve. It can be attributed to the existence of more than one type of the [SiO4] structural units36. Also, it can be clearly observed that the intensity of Raman peaks decrease sharply with SCLA addition. Raman bands in R-75 spectrum have low intensity than bands in R-100 spectrum. While, further addition of SCLA results into complete diminish of the Raman bands. It may be possible that R-00, R-25 and R-50 are also Raman active but the peaks are too weak to be measured. When cristobalite phae transforms to another phases, then low wavenumber raman bands at 114, 232 and 420 cm−1 diasappear37. Hence, Raman spectra R-00, R-25 and R-50 glasses could not show any observable Raman bands due to absence of cristobalite phase. Generally, NBO-Si bond should exhibit the Raman band near 900 cm−1 38. However, in the present case, amount of alkali content is low, that’s why band at this position could not be observed (as shown in Fig. 4).


Agricultural wastes as a resource of raw materials for developing low-dielectric glass-ceramics.

Danewalia SS, Sharma G, Thakur S, Singh K - Sci Rep (2016)

Raman spectra of the quenched samples derived from agricultural waste ash.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834533&req=5

f4: Raman spectra of the quenched samples derived from agricultural waste ash.
Mentions: Figure 4 shows the Raman spectra for present glasses and glass-ceramics. Raman spectra mainly show three bands for R-100 and R-75 glass-ceramics i.e. ~114, 232 and 420 cm−1, respectively. On the other hand, R-50 glass shows a very feeble band ~148 cm−1. In addition to this, it is observed that the spectra of R-100 and R-75 exhibit higher band intensity at higher wavenumbers. It can be related to either thermal background or to the possible luminescence from the material31. The bands exhibit slight variation due to formation of NBOs and change in structural units32. In general, Raman bands in silica and silicate glasses fall in three regions namely, near 1060 and 1200 cm−1 with weak intensity, ~800 cm−1 with medium intensity and ~430 cm−1 with maximum intensity33. Disturbed short range order due to glass modifier ions may suppress the intensity of Raman bands. Hence, the low intensity bands disappeared and only high intensity bands could be visible in the present samples. The bands at ~114, 232 and 420 cm−1 are attributed to symmetric stretching of Si-O-Si bond in cristobalite (SiO2) phase3435. These Raman bands are asymmetric as indicated by the deviation from pure Gaussian curve. It can be attributed to the existence of more than one type of the [SiO4] structural units36. Also, it can be clearly observed that the intensity of Raman peaks decrease sharply with SCLA addition. Raman bands in R-75 spectrum have low intensity than bands in R-100 spectrum. While, further addition of SCLA results into complete diminish of the Raman bands. It may be possible that R-00, R-25 and R-50 are also Raman active but the peaks are too weak to be measured. When cristobalite phae transforms to another phases, then low wavenumber raman bands at 114, 232 and 420 cm−1 diasappear37. Hence, Raman spectra R-00, R-25 and R-50 glasses could not show any observable Raman bands due to absence of cristobalite phase. Generally, NBO-Si bond should exhibit the Raman band near 900 cm−1 38. However, in the present case, amount of alkali content is low, that’s why band at this position could not be observed (as shown in Fig. 4).

Bottom Line: Sugarcane leaves ash exhibits higher content of alkali metal oxides than rice husk ash, which reduces the melting point of the components due to eutectic reactions.The presence of less ordered augite phase enhances the dielectric permittivity as compared to cristobalite and tridymite phases.The glass-ceramics developed with adequately devitrified phases can be used in microelectronic devices and other dielectric applications.

View Article: PubMed Central - PubMed

Affiliation: School of Physics and Materials Science, Thapar University, Patiala-147004, India.

ABSTRACT
Agricultural waste ashes are used as resource materials to synthesize new glass and glass-ceramics. The as-prepared materials are characterized using various techniques for their structural and dielectric properties to check their suitability in microelectronic applications. Sugarcane leaves ash exhibits higher content of alkali metal oxides than rice husk ash, which reduces the melting point of the components due to eutectic reactions. The addition of sugarcane leaves ash in rice husk ash promotes the glass formation. Additionally, it prevents the cristobalite phase formation. These materials are inherently porous, which is responsible for low dielectric permittivity i.e. 9 to 40. The presence of less ordered augite phase enhances the dielectric permittivity as compared to cristobalite and tridymite phases. The present glass-ceramics exhibit lower losses than similar materials synthesized using conventional minerals. The dielectric permittivity is independent to a wide range of temperature and frequency. The glass-ceramics developed with adequately devitrified phases can be used in microelectronic devices and other dielectric applications.

No MeSH data available.


Related in: MedlinePlus