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Transparent glass and glass‐ceramic in the binary system NaPO 3 ‐Ta 2 O 5
Author(s) -
Marcondes Lia Mara,
Maestri Sérgio,
Sousa Bianca Paula,
Cunha Cristiano Ramos,
Evangelista Renato Oliveria,
Manzani Danilo,
Cassanjes Fabia Castro,
Poirier Gael Yves
Publication year - 2020
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.16885
Subject(s) - crystallization , materials science , raman spectroscopy , differential scanning calorimetry , fourier transform infrared spectroscopy , analytical chemistry (journal) , tantalum , thermal stability , ceramic , phosphate glass , mineralogy , infrared spectroscopy , crystallography , chemical engineering , chemistry , optics , composite material , physics , optoelectronics , organic chemistry , chromatography , doping , engineering , metallurgy , thermodynamics
Transparent and homogeneous tantalum phosphate glasses were prepared in the binary system (100‐ x )NaPO 3 ‐ x Ta 2 O 5 with x varying from 10 to 50 mol%. Thermal, structural, and optical properties, as well as crystallization mechanisms, were investigated by thermal analysis, X‐ray diffraction, Fourier‐transform infrared spectroscopy (FTIR) and Raman spectroscopies, optical absorption, transmission electron microscopy in terms of Ta 2 O 5 content. FTIR and Raman results support the tantalum insertion in the phosphate chains with [TaO 6 ] polyhedra cross‐linking the phosphate units. At higher Ta 2 O 5 content, [TaO 6 ] clusters are formed and connected to the phosphate network by P‐O‐Ta bonds. This structural evolution is in good agreement with the thermal features measured by differential scanning calorimetry (DSC) with a strong increase of the T g temperatures up to 920°C, high thermal stability against crystallization for low Ta 2 O 5 content and increasing of crystallization tendency for the most Ta‐concentrated samples. Besides, due to the progressive insertion of [TaO 6 ] units, the precipitation of Na 2 Ta 8 O 21 perovskite‐like phase was identified in the sample with 50 mol% of Ta 2 O 5 . The optimal heat treatment conditions were identified using DSC measurements and a transparent glass‐ceramic from 50NaPO 3 to 50Ta 2 O 5 composition was prepared. The obtaines glass‐ceramic has great potential for optical applications, such as host for rare‐earth ions, nonlinear optical materials, and ferroelectric domain.