TY - JOUR

T1 - The effect of hydrostatic compression on the crystal structure of glycinium phosphite

AU - Bogdanov, Nikita E.

AU - Korabel'nikov, Dmitry V.

AU - Fedorov, Igor A.

AU - Zakharov, Boris A.

AU - Boldyreva, Elena V.

PY - 2022/9/1

Y1 - 2022/9/1

N2 - The crystal structure of glycinium phosphite (GPI) was studied in the pressure range from ambient to 6.5 GPa at 293 K using single-crystal X-ray diffraction. The changes in the unit-cell volume and parameters were continuous and anisotropic. The major compression was observed normal to the direction of the spontaneous polarization that occurs in this structure during a ferroelectric phase transition on cooling, whereas the structural compression along the b axis coinciding with the 21 axis was almost zero. The effect of pressure on the hydrogen bonds linking the H2PO3 tetrahedra into zigzag chains along the c axis was different from that on the hydrogen bonds connecting the glycinium cations with the H2PO3 tetrahedra in the (b × c) plane. The discontinuous changes in the geometries of selected hydrogen bonds at about 1.21 GPa may be evidence of a phase transition, e.g. into an ordered ferroelectric phase (with ordered positions of protons). The anisotropy of compression of GPI in the ferroelectric state (at 0 K) was studied using DFT calculations taking into account dispersive van der Waals interactions. The calculations predicted negative linear compressibility along the b axis.

AB - The crystal structure of glycinium phosphite (GPI) was studied in the pressure range from ambient to 6.5 GPa at 293 K using single-crystal X-ray diffraction. The changes in the unit-cell volume and parameters were continuous and anisotropic. The major compression was observed normal to the direction of the spontaneous polarization that occurs in this structure during a ferroelectric phase transition on cooling, whereas the structural compression along the b axis coinciding with the 21 axis was almost zero. The effect of pressure on the hydrogen bonds linking the H2PO3 tetrahedra into zigzag chains along the c axis was different from that on the hydrogen bonds connecting the glycinium cations with the H2PO3 tetrahedra in the (b × c) plane. The discontinuous changes in the geometries of selected hydrogen bonds at about 1.21 GPa may be evidence of a phase transition, e.g. into an ordered ferroelectric phase (with ordered positions of protons). The anisotropy of compression of GPI in the ferroelectric state (at 0 K) was studied using DFT calculations taking into account dispersive van der Waals interactions. The calculations predicted negative linear compressibility along the b axis.

KW - DFT

KW - X-ray diffraction

KW - ferroelectrics

KW - glycinium phosphite

KW - high pressure

KW - hydrogen bonds

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85175963877&origin=inward&txGid=3d128dd843ca565e63a1704b4a0d693c

UR - https://www.mendeley.com/catalogue/a53918ad-be09-3995-b5a5-ef5ab09d813b/

U2 - 10.1107/S2052520622008289

DO - 10.1107/S2052520622008289

M3 - Article

VL - 78

SP - 756

EP - 762

JO - Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials

JF - Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials

SN - 2052-5192

IS - Pt 5

ER -