Orientational ordering of water molecules confined in beryl: A theoretical study

0577201 - FZÚ 2024 RIV US eng J - Journal Article
Klíč, Antonín - Janiš, Václav - Kadlec, Filip
Orientational ordering of water molecules confined in beryl: A theoretical study.
Physical Review B. Roč. 108, č. 6 (2023), č. článku 064101. ISSN 2469-9950. E-ISSN 2469-9969
R&D Projects: GA ČR(CZ) GA20-01527S
Institutional support: RVO:68378271
Keywords : ferroelectrics * phase transitions * mean field theory * Monte Carlo methods
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.7, year: 2022
Method of publishing: Limited access
https://doi.org/10.1103/PhysRevB.108.064101

We present an improved model for studying the interactions between dipole moments of water molecules confined in beryl crystals inspired by recent NMR experiments. Our model is based on a local crystal potential with dihexagonal symmetry for the rotations of water dipole moments, leading to deflection from the ab hexagonal crystallographic plane. This potential shape has significant implications for dipole ordering, which is linked to the nonzero projection of the dipole moment on the hexagonal c axis. To reveal the tendency toward equilibrium-ordered states, we used a variational mean-field approximation, Monte Carlo simulations, and quantum tunneling. Our analysis reveals three types of equilibrium-ordered states: a purely planar dipole order with an antiparallel arrangement in the adjacent ab planes, a configuration with deflected dipole moments ordered in antiparallel directions, and a helical structure of the dipoles twisting along the c axis.
Permanent Link: https://hdl.handle.net/11104/0346419