Broad-band spectroscopy of nanoconfined water molecules

0536076 - FZÚ 2021 RIV US eng C - Konferenční příspěvek (zahraniční konf.)
Belyanchikov, M. A. - Savinov, Maxim - Bedran, Z.V. - Bednyakov, Petr - Proschek, P. - Prokleška, J. - Torgashev, V. I. - Zhukova, E.S. - Zhukov, S.S. - Kadyrov, L.S. - Thomas, V. - Dudka, A. - Zhugayevych, A. - Anzin, V.B. - Kremer, R. K. - Fischer, J.K.H. - Lunkenheimer, P. - Loidl, A. - Uykur, E. - Dressel, M. - Gorshunov, B.
Broad-band spectroscopy of nanoconfined water molecules.
IFMBE Proceedings. Vol. 77. New York: Springer International Publishing, 2020 - (Tiginyanu, I.; Sontea, V.; Railean, S.), s. 7-11. ISBN 978-3-030-31865-9. ISSN 1680-0737.
[4th International Conference on Nanotechnologies and Biomedical Engineering (ICNBME-2019). Chisinau (MD), 18.09.2019-21.09.2019]
Grant CEP: GA MŠMT(CZ) EF16_019/0000760; GA ČR GA15-08389S
Grant ostatní: OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institucionální podpora: RVO:68378271
Klíčová slova: quantum criticality * relaxations * soft phonon * nanoconfined water * ferroelectricity * spectroscopy
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)

We have performed broad-band spectroscopic investigations of vibrational and relaxational excitations of water molecules confined to nanocages within artificial beryl and mineral cordierite crystals. Signatures of quantum critical phenomena within the H2O molecular network are registered in beryl. In cordierite, a density functional analysis is applied to reconstruct the potential energy landscape experienced by H2O molecules, revealing a pronounced anisotropy with a potential well of about 10 meV for the molecular dipole moment aligned along the b-axis.This anisotropy leads to a strongly temperature dependent and anisotropic relaxational response of the dipoles at radiofrequencies with the activation energies corresponding to the barriers of the rotational potential. At T≈3 K, we identify signatures of a transition onto a glassy state composed by clusters of H2O dipoles.

Trvalý link: http://hdl.handle.net/11104/0313920