Structural stability of NaPON glass upon heating in air and nitrogen

Georgiana-Laura Paraschiv, Francisco Munoz, Lars Rosgaard Jensen, Yuanzheng Yue, Morten Mattrup Smedskjær

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

3 Citationer (Scopus)

Resumé

The thermal stability in air and nitrogen of an oxynitride NaPON glass with high nitrogen content (N/P = 0.5) has been investigated with regards to its structural evolution with temperature. The glass transition temperature (T g) of the powdered glass is found to decrease upon oxidation, especially when the treatment temperature (T a) is larger than the T g of the original oxynitride glass. Upon isothermal oxidation, crystalline metaphosphate forms at the interface of the oxide layer as the dominant phase in both the powder and bulk samples, as detected by Raman spectroscopy and X-ray diffraction. A new deconvolution scheme of Raman spectra is proposed, involving a structural model proposed to account for the in situ high temperature changes of the local structural groups. A distinction is made between different oxynitride Q n(P,N) tetrahedral sites, and two separate bands related to tri-coordinated nitrogen speciation (N t) are distinguished in the oxidized NaPON glass. N t groups are connected to either one oxygen or one nitrogen, resulting in two separate Raman bands. The position and area of these N t-related peaks exhibit an opposite trend with temperature in air and N 2. Furthermore, the Raman results imply a thermally driven depolymerization of the oxynitride sub-structure, which could involve a nano-scale phase separation of the nitrogen-involved structure network. In terms of technological applications, this work suggests that the oxynitride glasses should be used in the temperature range up to the glass transition temperature, above which the structural stability is lost.

OriginalsprogEngelsk
TidsskriftJournal of Non-Crystalline Solids
Vol/bind482
Sider (fra-til)137-146
Antal sider10
ISSN0022-3093
DOI
StatusUdgivet - 15 feb. 2018

Fingerprint

oxynitrides
structural stability
Nitrogen
Heating
nitrogen
Glass
heating
glass
air
Air
glass transition temperature
Temperature
depolymerization
Oxidation
Depolymerization
oxidation
temperature
Deconvolution
Phase separation
Powders

Citer dette

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title = "Structural stability of NaPON glass upon heating in air and nitrogen",
abstract = "The thermal stability in air and nitrogen of an oxynitride NaPON glass with high nitrogen content (N/P = 0.5) has been investigated with regards to its structural evolution with temperature. The glass transition temperature (T g) of the powdered glass is found to decrease upon oxidation, especially when the treatment temperature (T a) is larger than the T g of the original oxynitride glass. Upon isothermal oxidation, crystalline metaphosphate forms at the interface of the oxide layer as the dominant phase in both the powder and bulk samples, as detected by Raman spectroscopy and X-ray diffraction. A new deconvolution scheme of Raman spectra is proposed, involving a structural model proposed to account for the in situ high temperature changes of the local structural groups. A distinction is made between different oxynitride Q n(P,N) tetrahedral sites, and two separate bands related to tri-coordinated nitrogen speciation (N t) are distinguished in the oxidized NaPON glass. N t groups are connected to either one oxygen or one nitrogen, resulting in two separate Raman bands. The position and area of these N t-related peaks exhibit an opposite trend with temperature in air and N 2. Furthermore, the Raman results imply a thermally driven depolymerization of the oxynitride sub-structure, which could involve a nano-scale phase separation of the nitrogen-involved structure network. In terms of technological applications, this work suggests that the oxynitride glasses should be used in the temperature range up to the glass transition temperature, above which the structural stability is lost.",
author = "Georgiana-Laura Paraschiv and Francisco Munoz and Jensen, {Lars Rosgaard} and Yuanzheng Yue and Smedskj{\ae}r, {Morten Mattrup}",
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Structural stability of NaPON glass upon heating in air and nitrogen. / Paraschiv, Georgiana-Laura; Munoz, Francisco; Jensen, Lars Rosgaard; Yue, Yuanzheng; Smedskjær, Morten Mattrup.

I: Journal of Non-Crystalline Solids, Bind 482, 15.02.2018, s. 137-146.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Structural stability of NaPON glass upon heating in air and nitrogen

AU - Paraschiv, Georgiana-Laura

AU - Munoz, Francisco

AU - Jensen, Lars Rosgaard

AU - Yue, Yuanzheng

AU - Smedskjær, Morten Mattrup

PY - 2018/2/15

Y1 - 2018/2/15

N2 - The thermal stability in air and nitrogen of an oxynitride NaPON glass with high nitrogen content (N/P = 0.5) has been investigated with regards to its structural evolution with temperature. The glass transition temperature (T g) of the powdered glass is found to decrease upon oxidation, especially when the treatment temperature (T a) is larger than the T g of the original oxynitride glass. Upon isothermal oxidation, crystalline metaphosphate forms at the interface of the oxide layer as the dominant phase in both the powder and bulk samples, as detected by Raman spectroscopy and X-ray diffraction. A new deconvolution scheme of Raman spectra is proposed, involving a structural model proposed to account for the in situ high temperature changes of the local structural groups. A distinction is made between different oxynitride Q n(P,N) tetrahedral sites, and two separate bands related to tri-coordinated nitrogen speciation (N t) are distinguished in the oxidized NaPON glass. N t groups are connected to either one oxygen or one nitrogen, resulting in two separate Raman bands. The position and area of these N t-related peaks exhibit an opposite trend with temperature in air and N 2. Furthermore, the Raman results imply a thermally driven depolymerization of the oxynitride sub-structure, which could involve a nano-scale phase separation of the nitrogen-involved structure network. In terms of technological applications, this work suggests that the oxynitride glasses should be used in the temperature range up to the glass transition temperature, above which the structural stability is lost.

AB - The thermal stability in air and nitrogen of an oxynitride NaPON glass with high nitrogen content (N/P = 0.5) has been investigated with regards to its structural evolution with temperature. The glass transition temperature (T g) of the powdered glass is found to decrease upon oxidation, especially when the treatment temperature (T a) is larger than the T g of the original oxynitride glass. Upon isothermal oxidation, crystalline metaphosphate forms at the interface of the oxide layer as the dominant phase in both the powder and bulk samples, as detected by Raman spectroscopy and X-ray diffraction. A new deconvolution scheme of Raman spectra is proposed, involving a structural model proposed to account for the in situ high temperature changes of the local structural groups. A distinction is made between different oxynitride Q n(P,N) tetrahedral sites, and two separate bands related to tri-coordinated nitrogen speciation (N t) are distinguished in the oxidized NaPON glass. N t groups are connected to either one oxygen or one nitrogen, resulting in two separate Raman bands. The position and area of these N t-related peaks exhibit an opposite trend with temperature in air and N 2. Furthermore, the Raman results imply a thermally driven depolymerization of the oxynitride sub-structure, which could involve a nano-scale phase separation of the nitrogen-involved structure network. In terms of technological applications, this work suggests that the oxynitride glasses should be used in the temperature range up to the glass transition temperature, above which the structural stability is lost.

U2 - 10.1016/j.jnoncrysol.2017.12.032

DO - 10.1016/j.jnoncrysol.2017.12.032

M3 - Journal article

VL - 482

SP - 137

EP - 146

JO - Journal of Non-Crystalline Solids

JF - Journal of Non-Crystalline Solids

SN - 0022-3093

ER -