Partially proton-ordered ice I (cubic) was grown from the vapor phase, from 40 to nearly 150 K. It is believed to be metastable and oriented by the asymmetry of the solid−vacuum interface during growth. This was studied using a Kelvin (work function) probe for ice grown on a single-crystal Pt(111) substrate. The ice grows with a slight preference for the O-end aimed away from the surface, with about 0.2% net up dipole per water molecule at 40 K, or about −3 mV/monolayer of deposited ice film. This decreases with deposition temperature as exp(−T/27 K). Near 130, 140, and 150 K sharp features occur as the ice changes from amorphous to crystalline, and dielectric properties become active. By 150 K the effect seems to be zero. These results are discussed in context with other recent reports on ferroelectric ice. In addition to influencing several kinds of vacuum-based studies of ice, this slight ferroelectricity may allow natural ice vapor-grown in space to develop large electric fields.

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D 3 O 1 and Cs 1 ions ͑#1 eV͒ were soft landed on vacuum-deposited amorphous water ice at 30 K. The samples charged capacitively with an initial dielectric constant of 2. Then the voltage was measured via a Kelvin probe while the sample temperature was ramped. A sharp drop in voltage occurred near 50 K, due to dielectric responses occurring at much less than the expected 135 K. This was due to relaxations of the highly strained amorphous ice. Preannealing the ice could move the electrical relaxation up to as high as 120 K. Ion migration through the ice was not observed below 190 K.