Single crystals of phenakite-like Be2(Si1−xGex)O4 solid solution: novel experimental data on hydrothermal crystal growth, X-ray diffraction and Raman spectroscopy study. / Kovalev, Valentin; Thomas, Victor; Setkova, Tatiana et al.
In: Physics and Chemistry of Minerals, Vol. 50, No. 3, 20, 09.2023.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Single crystals of phenakite-like Be2(Si1−xGex)O4 solid solution: novel experimental data on hydrothermal crystal growth, X-ray diffraction and Raman spectroscopy study
AU - Kovalev, Valentin
AU - Thomas, Victor
AU - Setkova, Tatiana
AU - Zubkova, Natalia
AU - Spivak, Anna
AU - Fursenko, Dmitry
AU - Yapaskurt, Vasiliy
AU - Antipin, Alexander
AU - Borovikova, Elena
N1 - The crystal growth experiments were carried out on state assignment of IGM SB RAS with a technical support of LLC «TAIRUS» (Novosibirsk). This study was fulfilled under Research program № FMUF-2022-0002 of the Korzhinski Institute of Experimental Mineralogy (Chernogolovka, Moscow region). The single crystals X-ray diffraction study was performed using the equipment of the Shared Research Center FSRC “Crystallography and Photonics” RAS within the State assignment of the FSRC «Crystallography and Photonics». We thank Dr. S.G. Simakin and Mr. E.V. Potapov (Facilities Sharing Centre “Diagnostics of Micro- and Nanostructures, Yaroslavl) for SIMS investigation of samples. Публикация для корректировки.
PY - 2023/9
Y1 - 2023/9
N2 - The pioneering hydrothermal synthesis of the compound Be2[(Si1−xGex)O4] with a phenakite structure (the size of individual crystals up to 1 mm) was carried out in acidic alkaline-containing fluoride solutions at a temperature of 625 °C and a pressure of ~ 150 MPa. Uniform (x = 0, 0.80 and 1) and zonal (x = 0.04 − 0.025) Be2[(Si1−xGex)O4] crystals synthesized in the Li-containing mineralizer were obtained. The possibility of formation of intermediate compounds under hydrothermal conditions remains an open question. In the Na-containing mineralizer, only Be2SiO4 crystallizes due to the formation of insoluble sodium germanates. The fading of formation of Be2[(Si1−xGex)O4] was determined with the use of technique of temperature-induced zoning and can be explained by the fact that newly formed crystals screen the surface of the initial BeO. The instantaneous growth rates of the prismatic faces of Ge-substituted phenakite crystals, decreasing from 18 microns/day to 2, were determined using the technique of temperature-induced zonality. The crystal structures of Be2[(Si1−xGex)O4] samples with x = 0, 0.80 and 1 were refined by direct X-ray diffraction methods, and the linear dependence of the unit cell parameters and bond lengths on the germanium content has been quantitively described. First Raman spectroscopy study of Be2[(Si1−xGex)O4] on zonal crystals indicated the linear shift of vibration bands in Raman spectra to a lower frequencies with an increase in germanium concentration (x up to 0.25). A new Raman band of Ge–O stretching vibrations at ~ 1115 cm−1, which is not common for natural and synthetic germanium-free phenakites, was observed.
AB - The pioneering hydrothermal synthesis of the compound Be2[(Si1−xGex)O4] with a phenakite structure (the size of individual crystals up to 1 mm) was carried out in acidic alkaline-containing fluoride solutions at a temperature of 625 °C and a pressure of ~ 150 MPa. Uniform (x = 0, 0.80 and 1) and zonal (x = 0.04 − 0.025) Be2[(Si1−xGex)O4] crystals synthesized in the Li-containing mineralizer were obtained. The possibility of formation of intermediate compounds under hydrothermal conditions remains an open question. In the Na-containing mineralizer, only Be2SiO4 crystallizes due to the formation of insoluble sodium germanates. The fading of formation of Be2[(Si1−xGex)O4] was determined with the use of technique of temperature-induced zoning and can be explained by the fact that newly formed crystals screen the surface of the initial BeO. The instantaneous growth rates of the prismatic faces of Ge-substituted phenakite crystals, decreasing from 18 microns/day to 2, were determined using the technique of temperature-induced zonality. The crystal structures of Be2[(Si1−xGex)O4] samples with x = 0, 0.80 and 1 were refined by direct X-ray diffraction methods, and the linear dependence of the unit cell parameters and bond lengths on the germanium content has been quantitively described. First Raman spectroscopy study of Be2[(Si1−xGex)O4] on zonal crystals indicated the linear shift of vibration bands in Raman spectra to a lower frequencies with an increase in germanium concentration (x up to 0.25). A new Raman band of Ge–O stretching vibrations at ~ 1115 cm−1, which is not common for natural and synthetic germanium-free phenakites, was observed.
KW - Crystal growth
KW - Germanium
KW - Phenakite
KW - Raman spectroscopy
KW - Solid solution
KW - X-ray diffraction
UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85163896601&origin=inward&txGid=4a02ab44d4128e9357b0da924d7a22ea
UR - https://www.mendeley.com/catalogue/4659cd59-54a2-3c8a-9580-5194cc9ea739/
U2 - 10.1007/s00269-023-01245-6
DO - 10.1007/s00269-023-01245-6
M3 - Article
VL - 50
JO - Physics and Chemistry of Minerals
JF - Physics and Chemistry of Minerals
SN - 0342-1791
IS - 3
M1 - 20
ER -
ID: 59265122