0482555 - ÚTAM 2019 RIV US eng J - Journal Article
Ševčík, Radek - Šašek, Petr - Viani, Alberto
Physical and nanomechanical properties of the synthetic anhydrous crystalline CaCO3 polymorphs: vaterite, aragonite and calcite.
Journal of Materials Science. Roč. 53, č. 6 (2018), s. 4022-4033. ISSN 0022-2461. E-ISSN 1573-4803
R&D Projects: GA MŠMT(CZ) LO1219; GA ČR(CZ) GA17-05030S
Keywords : X-ray-diffraction * thermal expansion * mechanical characterization * relative-humidity * carbonates * mortars
OECD category: Inorganic and nuclear chemistry
Impact factor: 3.442, year: 2018 ; AIS: 0.558, rok: 2018
Result website:
https://doi.org/10.1007/s10853-017-1884-xDOI: https://doi.org/10.1007/s10853-017-1884-x

The synthetic anhydrous crystalline CaCO3 polymorphs—vaterite, aragonite and calcite—were tested using dilatometry and nanoindentation. Microstructural changes in the samples before and after measurements were observed under scanning electron microscope and their phase composition quantified with X-ray powder diffraction (XRPD) with the Rietveld method. The thermal expansion coefficients of vaterite and the hardness and elastic modulus of synthetic aragonite are reported for the first time. The physical and nanomechanical properties were measured under similar conditions for each CaCO3 polymorph. Aragonite, calcite and vaterite showed volumetric thermal expansion coefficient at 303 K of 49.2(8), 48.6(2) and 44.1(3) 10−6 K−1, respectively. The elastic modulus increased from 5(4), 16(7) to 31(8) GPa for aragonite, calcite and vaterite, respectively. Average hardness was found lower than values from the literature, ranging from 0.3 to 1.3 GPa. The results are considered of interest for the design of CaCO3-based materials for applications.
Permanent Link: http://hdl.handle.net/11104/0281952