Incipient ferroelectricity of water molecules confined to nano-channels of beryl

Abstract

Water is characterized by large molecular electric dipole moments and strong interactions between molecules; however, hydrogen bonds screen the dipole–dipole coupling and suppress the ferroelectric order. The situation changes drastically when water is confined: in this case ordering of the molecular dipoles has been predicted, but never unambiguously detected experimentally. In the present study we place separate H2O molecules in the structural channels of a beryl single crystal so that they are located far enough to prevent hydrogen bonding, but close enough to keep the dipole–dipole interaction, resulting in incipient ferroelectricity in the water molecular subsystem. We observe a ferroelectric soft mode that causes Curie–Weiss behaviour of the static permittivity, which saturates below 10 K due to quantum fluctuations. The ferroelectricity of water molecules may play a key role in the functioning of biological systems and find applications in fuel and memory cells, light emitters and other nanoscale electronic devices.

Effect of Hydrogen Bonds on the Dielectric Properties of Interfacial Water

“…This preferential orientation of the water molecules is also the reason for the nonzero polarization observed (Figure 2a) close to the channel walls even at no external field, suggesting a spontaneous ferroelectric behavior for the interfacial water molecules. 48 Reorientation Times of Water Molecules under Confinement. We analyze the rotational and reorientational dynamics of water from the time correlation function C l defined as 49…”

Piezoelectric poly(lactide) stereocomplexes with a cholinium organic ionic plastic crystal

“…45 A recent report of the incipient ferroelectricity of oriented water molecules confined to the nano-channels of a crystal raises the possibility that also the residual water trapped by choline in the stereocomplex structures could contribute to the observed PFM signal. 46 The piezoresponse could also result from a local distortion of the PLLA and PDLA molecules in the SC, which could have a stretching effect similar to changes in the orientation of the CQO dipoles occurring in the shear ferroelectricity of PLA, 9,10 or a confinement-induced cooperative molecular orientation, 30,31 given the particular location of the SC at the spherulitic interfaces. Further detailed studies of the composition, structure and local piezoresponse of samples with large SC crystalline domains are necessary in order to clarify the underlying mechanism behind the observed PFM data, and, if possible, to fully exploit the potential of PLA SCs to produce new materials with the controlled piezoelectric performance for biomedical applications.…”

Субмиллиметровые спектры ЭПР иона Fe-=SUP=-2+-=/SUP=- в кристаллах синтетического и природного бериллов

“…Недавно свой-ства воды в берилле были исследованы нами методами диэлектрической терагерцeвой спектроскопии [10,11]. B частности, было показано, что пространственно-структурированное расположение воды в каналах берил-ла приводит к виртуальному сегнетоэлектричеству [12]. Важным обстоятельством является также возможное влияние воды на спектры ЭПР, что описано далее.…”