Research output: Contribution to journal › Article › peer-review
Thermal Evolution and Crystal Structure Features of Cs2SO4 and Cs2Ca3(SO4)4 Sulfates. / Shablinskii, A. P.; Demina, S. V.; Biryukov, Y. P.; Bubnova, R. S.; Krzhizhanovskaya, M. G.; Filatov, S. K.
In: Crystallography Reports, Vol. 70, No. 3, 01.06.2025, p. 358-368.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Thermal Evolution and Crystal Structure Features of Cs2SO4 and Cs2Ca3(SO4)4 Sulfates
AU - Shablinskii, A. P.
AU - Demina, S. V.
AU - Biryukov, Y. P.
AU - Bubnova, R. S.
AU - Krzhizhanovskaya, M. G.
AU - Filatov, S. K.
PY - 2025/6/1
Y1 - 2025/6/1
N2 - Abstract: The thermal expansion of two modifications α- and β-Cs2SO4, as well as the compound Cs2Ca3(SO4)4, was studied for the first time by high-temperature powder X-ray diffraction method in the temperature ranges of 25–960 and 25–540°C, respectively. β-Cs2SO4 transforms into the high-temperature α-Cs2(SO4) modification through a two-phase region in the range of 600–750°C. The thermal expansion of all studied phases is sharply anisotropic: αa = 37.3(10), αb = 36.2(4), αc = 12(5), αV = 85.1(5) at 30°C for β-Cs2SO4; αa = 55(5), αc = 115(9), αV = 224(12) × 10–6 °С–1 at 750°С for α-Cs2SO4. The thermal expansion coefficients for Cs2Ca3(SO4)4 are α11 = 18.8(5), αb = 18.2(5), α33 = –7.5(2), αβ = –10.6(2), αV = 29.6(9) × 10–6 °С–1 at 25°С. The continuity of the polymorphic transformation of Cs2SO4 is shown. It consists in the fact that, with an increase in temperature, the corrugated columns or rods elongated along the c axis in both modifications, consisting of Cs(SO4)6 microblocks, straighten due to the rotation of SO4 tetrahedra. The interpretation of the anisotropy of the thermal expansion of Cs2Ca3(SO4)4 is based on the mechanism of rocking polyhedra. A hinge deformation at the level of Ca(SO4)6 microblocks, which leads to a large negative thermal expansion in the α33 direction, is revealed.
AB - Abstract: The thermal expansion of two modifications α- and β-Cs2SO4, as well as the compound Cs2Ca3(SO4)4, was studied for the first time by high-temperature powder X-ray diffraction method in the temperature ranges of 25–960 and 25–540°C, respectively. β-Cs2SO4 transforms into the high-temperature α-Cs2(SO4) modification through a two-phase region in the range of 600–750°C. The thermal expansion of all studied phases is sharply anisotropic: αa = 37.3(10), αb = 36.2(4), αc = 12(5), αV = 85.1(5) at 30°C for β-Cs2SO4; αa = 55(5), αc = 115(9), αV = 224(12) × 10–6 °С–1 at 750°С for α-Cs2SO4. The thermal expansion coefficients for Cs2Ca3(SO4)4 are α11 = 18.8(5), αb = 18.2(5), α33 = –7.5(2), αβ = –10.6(2), αV = 29.6(9) × 10–6 °С–1 at 25°С. The continuity of the polymorphic transformation of Cs2SO4 is shown. It consists in the fact that, with an increase in temperature, the corrugated columns or rods elongated along the c axis in both modifications, consisting of Cs(SO4)6 microblocks, straighten due to the rotation of SO4 tetrahedra. The interpretation of the anisotropy of the thermal expansion of Cs2Ca3(SO4)4 is based on the mechanism of rocking polyhedra. A hinge deformation at the level of Ca(SO4)6 microblocks, which leads to a large negative thermal expansion in the α33 direction, is revealed.
UR - https://www.mendeley.com/catalogue/81d3a38b-6f31-37ba-b1ec-1944b34b2615/
U2 - 10.1134/s106377452460296x
DO - 10.1134/s106377452460296x
M3 - Article
VL - 70
SP - 358
EP - 368
JO - Crystallography Reports
JF - Crystallography Reports
SN - 1063-7745
IS - 3
ER -
ID: 141438726