| Full text | |
| Author(s): Show less - |
Gammond, Lawrence V. D.
[1]
;
Auer, Henry
[2]
;
Da Silva, Rita Mendes
[1]
;
Zeidler, Anita
[1]
;
Ortiz-Mosquera, Jairo F.
[3]
;
Nieto-Munoz, Adriana M.
[3]
;
Rodrigues, Ana Candida M.
[4]
;
Almeida Silva, Igor D'Anciaes
[5]
;
Eckert, Hellmut
[6, 5]
;
Benmore, Chris J.
[7]
;
Salmon, Philip S.
[1]
Total Authors: 11
|
| Affiliation: | [1] Univ Bath, Dept Phys, Bath BA2 7AY, Avon - England
[2] Fraunhofer Inst Ceram Technol & Syst IKTS, Winterbergstr 28, D-01277 Dresden - Germany
[3] Univ Fed Sao Carlos, Programa Posgrad Cincia & Engn Mat, CP 676, BR-13565905 Sao Carlos, SP - Brazil
[4] Univ Fed Sao Carlos, Dept Engn Mat, CP 676, BR-13565905 Sao Carlos, SP - Brazil
[5] Univ Sao Paulo, Inst Fis Sao Carlos, CP 369, BR-13566590 Sao Carlos, SP - Brazil
[6] WWU Munster, Inst Phys Chem, Corrensstr 30, D-48149 Munster - Germany
[7] Argonne Natl Lab, Xray Sci Div, Adv Photon Source, 9700 South Cass Ave, Lemont, IL 60439 - USA
Total Affiliations: 7
|
| Document type: | Journal article |
| Source: | Journal of Chemical Physics; v. 155, n. 7 AUG 21 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
The structure of crystalline and amorphous materials in the sodium (Na) super-ionic conductor system Na1+xAlxGe2-x(PO4)(3) with x = 0, 0.4, and 0.8 was investigated by combining (i) neutron and x-ray powder diffraction and pair-distribution function analysis with (ii) Al-27 and P-31 magic angle spinning (MAS) and P-31/Na-23 double-resonance nuclear magnetic resonance (NMR) spectroscopy. A Rietveld analysis of the powder diffraction patterns shows that the x = 0 and x = 0.4 compositions crystallize into space group-type R3, whereas the x = 0.8 composition crystallizes into space group-type R3c. For the as-prepared glass, the pair-distribution functions and Al-27 MAS NMR spectra show the formation of sub-octahedral Ge and Al centered units, which leads to the creation of non-bridging oxygen (NBO) atoms. The influence of these atoms on the ion mobility is discussed. When the as-prepared glass is relaxed by thermal annealing, there is an increase in the Ge and Al coordination numbers that leads to a decrease in the fraction of NBO atoms. A model is proposed for the x = 0 glass in which super-structural units containing octahedral Ge-(6) and tetrahedral P-(3) motifs are embedded in a matrix of tetrahedral Ge-(4) units, where superscripts denote the number of bridging oxygen atoms. The super-structural units can grow in size by a reaction in which NBO atoms on the P-(3) motifs are used to convert Ge-(4) to Ge-(6) units. The resultant P-(4) motifs thereby provide the nucleation sites for crystal growth via a homogeneous nucleation mechanism. Published under an exclusive license by AIP Publishing. (AU) | |
| FAPESP's process: | 17/17800-0 - Solid State NMR for the study of structure/property correlations in glassy and glass ceramic materials for energy storage applications |
| Grantee: | Igor d'Anciães Almeida Silva |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass |
| Grantee: | Edgar Dutra Zanotto |
| Support Opportunities: | Research Grants - Research, Innovation and Dissemination Centers - RIDC |