Crystallization of sodium molybdate-phosphate and tungstate-phosphate glasses

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F18%3A39912722" target="_blank" >RIV/00216275:25310/18:39912722 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1016/j.jnoncrysol.2017.09.040" target="_blank" >http://dx.doi.org/10.1016/j.jnoncrysol.2017.09.040</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jnoncrysol.2017.09.040" target="_blank" >10.1016/j.jnoncrysol.2017.09.040</a>

Result language

angličtina

Original language name

Crystallization of sodium molybdate-phosphate and tungstate-phosphate glasses

Original language description

The glass to crystal transformation was studied for two glasses with composition 25Na(2)center dot O.50MoO(3)center dot 25P(2)O(6) and 25Na(2)O center dot 50WO(3)center dot 25P(2)O(5). During the heat treatment process, two crystalline compounds were formed, NaMoO2PO4 and NaWO2PO4, respectively. Physico-chemical properties of the corresponding glasses and crystals were compared, as well as their Raman and P-31 MAS NMR spectra. Differential thermal analysis revealed crystallization peaks at 483 degrees C for the Mo-containing glass and at 624 degrees C for the W-containing glass; melting points of crystalline compounds were determined as 695 +/- 2 degrees C for NaMoO2PO4 and 858 +/- 2 degrees C for NaMoO2PO4. Sodium tungstate-phosphate glass has lower solubility in comparison with the sodium molybdatephosphate glass. The study of the crystallization mechanism showed a prevailing surface nucleation. P-31 MAS NMR spectra of the two glasses revealed the same shape and almost the same width, which reflects a similar local environment for P in these glasses. The position of the resonance for W-containing glass at a more negative chemical shift than the Mo-containing one is attributed to the different electrical field strength of W atoms than Mo atoms. P-31 MAS NMR spectra of crystals revealed two resonances at + 17 and -0.5 ppm for the Mo glass and at -0.1 and -1.9 ppm for the W glass, reflecting the presence of two different phosphorus short range environments, in agreement with their crystal structure. Raman spectra showed similarity in structural features for Mo and W glasses and their isomorphic compounds. Splitting of the dominant Raman bands in the crystal spectra reflects a distortion of MoO6 and WO6 octahedra. Raman spectra also suggested the breaking of Mo-O-Mo and WOW linkages during crystallization.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

<a href="/en/project/GA18-01976S" target="_blank" >GA18-01976S: New prospective phosphate and borophosphate glasses and glass-ceramics</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

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

Name of the periodical

Journal of Non-Crystalline Solids

ISSN

0022-3093

e-ISSN

—

Volume of the periodical

500

Issue of the periodical within the volume

November

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

7

Pages from-to

42-48

UT code for WoS article

000447096600006

EID of the result in the Scopus database

2-s2.0-85048495041