PROTONIC PHOTOCONDUCTIVITY OF ICE

HAL Id: jpa-00226458

https://hal.archives-ouvertes.fr/jpa-00226458

Submitted on 1 Jan 1987

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

PROTONIC PHOTOCONDUCTIVITY OF ICE

V. Petrenko, T. Ebinuma, N. Maeno

To cite this version:

V. Petrenko, T. Ebinuma, N. Maeno. PROTONIC PHOTOCONDUCTIVITY OF ICE. Journal de

Physique Colloques, 1987, 48 (C1), pp.C1-649-C1-649. �10.1051/jphyscol:1987192�. �jpa-00226458�

JOURNAL DE PHYSIQUE

Colloque C1, supplement au n o 3, Tome 48, mars 1987

V.F. PETRENKO, T. EBINUMA* and N. MAENO*

The Institute of Solid State Physics, The USSR Academy of Sciences, Chernogolovka 142432, Moscow District, USSR

"The Institute of Low Temperature Sciences, Hokkaido University, Sapporo 060, Japan

Abstract : A number of attempts have been made to find the protonic phot~~~nductivity of ice (abbreviated as FTC hereafter), but most of them were not successful. Camp and Spears (1) tried to excite PPC of pure ice single crystals by a xenon lamp and concluded that the probability of photodissociation of ice, if any, is very small. De Haas et dl. (2) and Itagaki et al. (3) used gannna-rays, X-rays, or electron beams, and found a change in the electrical conductivity. Very high-energy beams were used in these experiments, hawever, which yielded radiation-induced damage and defects in the bulk specimen.

PPC was observed in ice doped with o- nitrobenzoaldehyde (abbreviated as NBAld ;

ice was gram from aquaus solution of -d at the concentration of 6.6 r lo-& M (moles per liter) and cut into a plate' of 4 mn in thickness. Network or disk electrodes were fixed to the ice sample, to which ultraviolet rays were emitted by using a xenon lamp of 300 W. Conductivities and capacitances were measured by using a bridge and null detector at frequencies between 30 Hz and 30 kHz.

Both the conductance and capacitance were found to increase when the ice sample was illuminated by the ultraviolet light, however the increase in conductance was noted to be larger than that in capacitance. It was also found that the increase in the limiting high-frequency conductivity was much larger than that in the low-frequency conductivity. The increasing rate of conductance with time shcued a maximum at the wavelength between 390 and 400 nm.

A theoretical rodel of FTC in NBAld-doped ice was introduced ; the model is based on the observation of Konstantinov et al. (4) that protons are released from NBAld by the ultraviolet illumination. It is further assumed that a photo-proton released creates an H30 ion and a Fdefect. Theoretically estimated increases in the conductivities were in good agreement with those observed.

The observed time-dependence of PPC was explained by the formation of small clusters of NBAld mlecules in ice ; estimated sizes of the clusters were roughly lpm.

Fef erences

(1) Camp, P.R. and

.

(2) De Haas, M.P. et dl., J. Phys. CHem., 87 (21) (1983), 4089.

(3) Itagaki, K. et al., J. Phys. Chem., 87 (21) (1983), 4114.

(4) Konstantinov, A.A. et al., Doklady Adademii Nauk USSR, 264 (2) (1982), 488.

("pirat published in J. Phys. Stat. Sol. (a) 93. 695-702 (1986)

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1987192