TY - JOUR

T1 - The evolution of yugawaralite structure at high pressure: A single-crystal X-ray diffraction study

AU - Seryotkin, Yurii V.

AU - Rashchenko, Sergey V.

AU - Likhacheva, Anna Yu

PY - 2024/10/1

Y1 - 2024/10/1

N2 - The structural evolution of yugawaralite |Ca1.93Na0.08(H2O)8.1|[Al3.94Si12.06O32], space group Pc, a = 6.72309(15), b = 13.9990(2), c = 10.0477(2) Å, β = 111.164(2)°, V = 881.87(3) Å3, compressed in penetrating (ethanol:water 4:1) and non-penetrating (paraffin oil) media, was studied up to 3.2 GPa. Under the compression in a penetrating medium, yugawaralite experiences pressure-induced hydration. Additional H2O molecules occupy two positions which do not enter the coordination of the extra-framework cations: one of them is partially filled under ambient conditions, and the second is initially vacant. At around 2 GPa, yugawaralite experiences a phase transition with doubling of the a- and b-parameters of the unit cell. At high pressure the diffraction frames contain sharply broadened low-intensity diffuse reflections corresponding to a multiple increase of the unit cell metric. The structure of the high-pressure phase solved in the sub-cell, corresponding to the initial metric, is characterized by the disordering of the framework sub-chains in which the SiO4-tetrahedra become alternatively oriented. The pressure-induced structural changes are completely reversible. The compression of yugawaralite in a non-penetrating medium does not lead to radical structural changes. The structure symmetry is preserved; there are no signs of diffuse scattering or the splitting of atomic positions.

AB - The structural evolution of yugawaralite |Ca1.93Na0.08(H2O)8.1|[Al3.94Si12.06O32], space group Pc, a = 6.72309(15), b = 13.9990(2), c = 10.0477(2) Å, β = 111.164(2)°, V = 881.87(3) Å3, compressed in penetrating (ethanol:water 4:1) and non-penetrating (paraffin oil) media, was studied up to 3.2 GPa. Under the compression in a penetrating medium, yugawaralite experiences pressure-induced hydration. Additional H2O molecules occupy two positions which do not enter the coordination of the extra-framework cations: one of them is partially filled under ambient conditions, and the second is initially vacant. At around 2 GPa, yugawaralite experiences a phase transition with doubling of the a- and b-parameters of the unit cell. At high pressure the diffraction frames contain sharply broadened low-intensity diffuse reflections corresponding to a multiple increase of the unit cell metric. The structure of the high-pressure phase solved in the sub-cell, corresponding to the initial metric, is characterized by the disordering of the framework sub-chains in which the SiO4-tetrahedra become alternatively oriented. The pressure-induced structural changes are completely reversible. The compression of yugawaralite in a non-penetrating medium does not lead to radical structural changes. The structure symmetry is preserved; there are no signs of diffuse scattering or the splitting of atomic positions.

KW - Diffuse scattering

KW - Phase transformation

KW - Pressure-induced hydration

KW - Single-crystal X-ray diffraction

KW - Yugawaralite

UR - https://www.mendeley.com/catalogue/db246116-091f-3aed-a9bd-83c125f68d6f/

U2 - 10.1016/j.matchemphys.2024.129753

DO - 10.1016/j.matchemphys.2024.129753

M3 - статья

VL - 325

JO - Materials Chemistry and Physics

JF - Materials Chemistry and Physics

SN - 0254-0584

M1 - 129753

ER -