Broadband spectroscopy of H2O molecule confined in nano-cages of crystal lattice: Low-energy dynamics and incipient ferroelectric behavior

Broadband (1 Hz to 100 THz) dielectric response of water-containing beryl crystals was measured at temperatures from 300 K down to 0.3 K. The low-energy dynamics of H
₂
O molecules confined within nano-cages of the crystalline lattice was studied. We observe a THz-range soft mode indicating an incipient ferroelectric behavior due to interacting dipole moments of confined water molecules.