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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

XRD patterns of the sample pelletsheat treated at 1000 °C for 10 h.
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f2: XRD patterns of the sample pelletsheat treated at 1000 °C for 10 h.

Mentions: Figure 2 shows the x-ray diffraction patterns of the heat-treated pellets, which were used for dielectric measurements. After the heat treatment, R-00, R-25 and R-50, which were amorphous in as-quenched condition, transformed to glass-ceramics. On the other hand, R-75 and R-100, retained their glass-ceramic nature. However, full width at half maxima (FWHM) of the XRD peaks increases in the heat-treated samples as compared to the quenched samples (R-75 and R-100). Also, the diffraction peaks shift towards higher diffraction angle after the heat-treatment. The broadening and shift of peaks is more prominent for R-75 as compared to R-100. The broadening of the characteristic peaks indicates that during the heat-treatment, the as-quenched phases start dissolving and/or transforming to other stable crystalline phases. The volume fraction of the major phase i.e. cristobalite decreases to 76% for R-75 and 91% R-100, respectively. The decrease is accompanied by corresponding increase in the volume fraction of tridymite phase. Interestingly, R-00 and R-25 formed cristobalite, SiO2 (ICDD No.-00-039-1425) and diopside aluminian, Ca(Mg0.5Al0.5)(Al0.5Si1.5O6)(ICDD No.-01-080-0409) after heat treatment. However, cristobalite is a high temperature phase and forms at temperatures >1470 °C2021. But, it has been reported that in the presence of alkali and alkaline earth content the cristobalite phase is formed even at low temperatures i.e. ~1000 °C19. It is well reported in the literature that the particle size of initial constituents can also play important role in the cristobalite phase formation22. R-50, with highest amount of modifying cations, shows distinguished XRD pattern than other glass-ceramics of the present series. Augite, Ca(Mg0.70Al0.30)((Si1.70Al0.30)O6) (ICDD No.-01-078-1392) is formed in this sample. Higher amount of modifying cations in R-50 hindered the formation of crystallised SiO2 phases. The nature and degree of crystallisation in these samples exhibits strong compositional dependence.


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)

XRD patterns of the sample pelletsheat treated at 1000 °C for 10 h.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2: XRD patterns of the sample pelletsheat treated at 1000 °C for 10 h.
Mentions: Figure 2 shows the x-ray diffraction patterns of the heat-treated pellets, which were used for dielectric measurements. After the heat treatment, R-00, R-25 and R-50, which were amorphous in as-quenched condition, transformed to glass-ceramics. On the other hand, R-75 and R-100, retained their glass-ceramic nature. However, full width at half maxima (FWHM) of the XRD peaks increases in the heat-treated samples as compared to the quenched samples (R-75 and R-100). Also, the diffraction peaks shift towards higher diffraction angle after the heat-treatment. The broadening and shift of peaks is more prominent for R-75 as compared to R-100. The broadening of the characteristic peaks indicates that during the heat-treatment, the as-quenched phases start dissolving and/or transforming to other stable crystalline phases. The volume fraction of the major phase i.e. cristobalite decreases to 76% for R-75 and 91% R-100, respectively. The decrease is accompanied by corresponding increase in the volume fraction of tridymite phase. Interestingly, R-00 and R-25 formed cristobalite, SiO2 (ICDD No.-00-039-1425) and diopside aluminian, Ca(Mg0.5Al0.5)(Al0.5Si1.5O6)(ICDD No.-01-080-0409) after heat treatment. However, cristobalite is a high temperature phase and forms at temperatures >1470 °C2021. But, it has been reported that in the presence of alkali and alkaline earth content the cristobalite phase is formed even at low temperatures i.e. ~1000 °C19. It is well reported in the literature that the particle size of initial constituents can also play important role in the cristobalite phase formation22. R-50, with highest amount of modifying cations, shows distinguished XRD pattern than other glass-ceramics of the present series. Augite, Ca(Mg0.70Al0.30)((Si1.70Al0.30)O6) (ICDD No.-01-078-1392) is formed in this sample. Higher amount of modifying cations in R-50 hindered the formation of crystallised SiO2 phases. The nature and degree of crystallisation in these samples exhibits strong compositional dependence.

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