Ferroelectricity in water ice

Fukazawa, Hiroshi

Whether or not ice in the Universe exists as ferroelectric is a question that has attracted scientific interest. The existence of a ferroelectric ice, named ice XI, at atmospheric pressure have been predicted; however it is not clear whether other ferroelectric ices exist or not under pressure, because of a difficulty of in-situ high-pressure neutron experiment. Our neutron study suggests that icy interior inside cool planets is a new ferroelectric ice. The super-dense ferroelectric ice, possessing the ability to carry a charge, could have had important effects on geological events on cool planets. Recent theoretical works also suggests that water also becomes ferroelectric in nano tube and small cage. We show that the ferroelectricity makes water ice more attractive.