Low Temperature Physics: 29, 805 (2003); https://doi.org/10.1063/1.1614198 (4 pages)
Физика Низких Температур: Том 29, Выпуск 9-10 (Сентябрь 2003), c. 1061-1064    ( к оглавлению , назад )

Observation of crystallization of amorphous solid water under the conditions of secondary emission mass spectrometric experiments

M.V. Kosevich, O.A. Boryak, V.S. Shelkovsky, and V.V. Orlov

B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine, 47 Lenin Ave., Kharkov 61103, Ukraine
E-mail: mvkosevich@ilt.kharkov.ua

Аннотация

A phenomenon of termination of sputtering of protonated water clusters (H2O)nH+ in low-temperature secondary emission mass spectrometric studies of solid water was observed in the temperature range of crystallization of amorphous solid water (ASW). In this range the mass spectra contained only H3O+, H2O+•, and OH+ ions. The following explanation of the revealed phenomenon is suggested: the heat supplied to the ASW sample by the bombarding particles is spent on initiation of an amorphous–crystalline transition within the condensed sample but not for the transfer of the sample matter to the gas phase. At the same time heat released on crystallization causes a local rise in temperature of the crystallizing sample surface, which enhances the rate of sublimation of ice. The resulting increased concentration of subliming water molecules over the sample surface is reflected in the growth of abundance of H2O+• molecular ion-radical, produced by gas-phase ionization mechanism. The appearance of a set of low-mass peaks in the course of crystallization observed for some types of ASW samples is explained by the release of gases trapped in the ASW film during its growth.

PACS:
68.49.Sf - Ion scattering from surfaces (charge transfer, sputtering, SIMS)
64.70.Kb - Solid-solid transitions (see also 61.50.Ks Crystallographic aspects of phase transformations; pressure effects; 75.30.Kz and 77.80.Bh for magnetic and ferroelectric transitions, respectively; for material science aspects, see 81.30.-t)
61.43.-j - Disordered solids (see also 81.05.Gc, 81.05.Kf, and 81.05.Rm in materials science; for photoluminescence of disordered solids, see 78.55.Mb and 78.55.Qr)
36.40.Wa - Charged clusters