TY - JOUR

T1 - Preparation of C12A7 nanoparticles by laser vaporization and their phase transformations during thermal treatment

AU - Kapishnikov, Aleksandr

AU - Snytnikov, Valeriy

AU - Gerasimov, Evgeniy

AU - Volodin, Vladimir

AU - Volodin, Alexander

AU - Geydt, Pavel

PY - 2024/11/22

Y1 - 2024/11/22

N2 - Nanodispersed systems with the stoichiometry of Ca12Al14O33 (12CaO·7Al2O3 or C12A7) have been prepared by vaporization of polycrystalline C12A7 target under the influence of continuous radiation from a CO2-laser in a He atmosphere with 0.2 bar pressure. The resulting powders were X-ray amorphous with well-developed specific surface area ∼115 m2/g and had characteristic nanoparticle sizes in the range of 20–30 nm. Despite the presence of different Ca-Al oxide impurities (CaO, Al2O3, Ca3Al2O6), the chemical composition of the resultant amorphous material was close to the stoichiometry of C12A7. The “in situ” X-ray diffraction (XRD) technique has been used to investigate the changes in the phase composition of the material under different (air or helium) gas environment in the temperature range of 100–900 °C. It has been demonstrated that the formation and recrystallization of the mayenite phase in nanoparticles system started in the temperature range of 700–800 °C, mostly independent of the oxidizing character of the gas environment (oxidizing or inert).

AB - Nanodispersed systems with the stoichiometry of Ca12Al14O33 (12CaO·7Al2O3 or C12A7) have been prepared by vaporization of polycrystalline C12A7 target under the influence of continuous radiation from a CO2-laser in a He atmosphere with 0.2 bar pressure. The resulting powders were X-ray amorphous with well-developed specific surface area ∼115 m2/g and had characteristic nanoparticle sizes in the range of 20–30 nm. Despite the presence of different Ca-Al oxide impurities (CaO, Al2O3, Ca3Al2O6), the chemical composition of the resultant amorphous material was close to the stoichiometry of C12A7. The “in situ” X-ray diffraction (XRD) technique has been used to investigate the changes in the phase composition of the material under different (air or helium) gas environment in the temperature range of 100–900 °C. It has been demonstrated that the formation and recrystallization of the mayenite phase in nanoparticles system started in the temperature range of 700–800 °C, mostly independent of the oxidizing character of the gas environment (oxidizing or inert).

KW - Crystallization

KW - Electride

KW - Laser vaporization

KW - Mayenite

KW - Nanopowder synthesis

UR - https://www.mendeley.com/catalogue/0d6d5193-90bb-31ca-84c6-81050da0687c/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85213942741&origin=inward&txGid=0422f4cc856d443bbbe46b4a08f9ae3b

U2 - 10.1016/j.ceramint.2024.11.343

DO - 10.1016/j.ceramint.2024.11.343

M3 - Article

JO - Ceramics International

JF - Ceramics International

SN - 0272-8842

ER -