Understanding the structural origin of crystalline phase transformations in nepheline (NaAlSiO4)-based glass-ceramics

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389013%3A_____%2F17%3A00475985" target="_blank" >RIV/61389013:_____/17:00475985 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1111/jace.14845" target="_blank" >http://dx.doi.org/10.1111/jace.14845</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/jace.14845" target="_blank" >10.1111/jace.14845</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Understanding the structural origin of crystalline phase transformations in nepheline (NaAlSiO4)-based glass-ceramics

Popis výsledku v původním jazyce

Nepheline (Na6K2Al8Si8O32) is a rock-forming tectosilicate mineral which is by far the most abundant of the feldspathoids. The crystallization in nepheline-based glass-ceramics proceeds through several polymorphic transformations - mainly orthorhombic, hexagonal, cubic - depending on their thermochemistry. However, the fundamental science governing these transformations is poorly understood. In this article, an attempt has been made to elucidate the structural drivers controlling these polymorphic transformations in nepheline-based glass-ceramics. Accordingly, two different sets of glasses (meta-aluminous and per-alkaline) have been designed in the system Na2O-CaO-Al2O3-SiO2 in the crystallization field of nepheline and synthesized by the melt-quench technique. The detailed structural analysis of glasses has been performed by 29Si, 27Al, and 23Na magic-angle spinning - nuclear magnetic resonance (MAS NMR), and multiple-quantum MAS NMR spectroscopy, while the crystalline phase transformations in these glasses have been studied under isothermal and non-isothermal conditions using differential scanning calorimetry (DSC), X-ray diffraction (XRD), and MQMAS NMR. Results indicate that the sequence of polymorphic phase transformations in these glass-ceramics is dictated by the compositional chemistry of the parent glasses and the local environments of different species in the glass structure. For example, the sodium environment in glasses became highly ordered with decreasing Na2O/CaO ratio, thus favoring the formation of hexagonal nepheline, while the cubic polymorph was the stable phase in SiO2–poor glass-ceramics with (Na2O+CaO)/Al2O3 > 1. The structural origins of these crystalline phase transformations have been discussed in the paper.

Název v anglickém jazyce

Understanding the structural origin of crystalline phase transformations in nepheline (NaAlSiO4)-based glass-ceramics

Popis výsledku anglicky

Nepheline (Na6K2Al8Si8O32) is a rock-forming tectosilicate mineral which is by far the most abundant of the feldspathoids. The crystallization in nepheline-based glass-ceramics proceeds through several polymorphic transformations - mainly orthorhombic, hexagonal, cubic - depending on their thermochemistry. However, the fundamental science governing these transformations is poorly understood. In this article, an attempt has been made to elucidate the structural drivers controlling these polymorphic transformations in nepheline-based glass-ceramics. Accordingly, two different sets of glasses (meta-aluminous and per-alkaline) have been designed in the system Na2O-CaO-Al2O3-SiO2 in the crystallization field of nepheline and synthesized by the melt-quench technique. The detailed structural analysis of glasses has been performed by 29Si, 27Al, and 23Na magic-angle spinning - nuclear magnetic resonance (MAS NMR), and multiple-quantum MAS NMR spectroscopy, while the crystalline phase transformations in these glasses have been studied under isothermal and non-isothermal conditions using differential scanning calorimetry (DSC), X-ray diffraction (XRD), and MQMAS NMR. Results indicate that the sequence of polymorphic phase transformations in these glass-ceramics is dictated by the compositional chemistry of the parent glasses and the local environments of different species in the glass structure. For example, the sodium environment in glasses became highly ordered with decreasing Na2O/CaO ratio, thus favoring the formation of hexagonal nepheline, while the cubic polymorph was the stable phase in SiO2–poor glass-ceramics with (Na2O+CaO)/Al2O3 > 1. The structural origins of these crystalline phase transformations have been discussed in the paper.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10404 - Polymer science

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of the American Ceramic Society

ISSN

0002-7820

e-ISSN

—

Svazek periodika

100

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

20

Strana od-do

2859-2878

Kód UT WoS článku

000404730100012

EID výsledku v databázi Scopus

2-s2.0-85017428987