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Experimental data on the structure, electrical and gas sensor properties of Sn-Y-O thin films with Y content from 0.4 to 4.8 at % are presented. The films have been prepared by reactive ion-beam deposition in argon atmosphere with oxygen addition. Composite target used in deposition procedure represents a tin plate with yttrium strips unevenly arranged on the plate surface. Such a target configuration allowed one to obtain 75 samples with yttrium concentration 0.4 to 4.8 at.% in one deposition cycle. The structure of the Sn-Y-O films in the initial state is amorphous. The crystallization process in the system studied is observed at temperatures of 400-500°C, and it begins with the formation of metastable SnO precipitates. The start temperature of the crystallization process increases with increasing of the Y content. Further increase of the temperature leads to a transformation of a part of the SnO phase into SnO 2 and formation of crystalline Y 2 O 3. The studies of electrical properties of the Sn-Y-O thin films in the initial state show that electrical resistivity measured at room temperature is higher than 10 10 Ohm • сm and decreases with an increase of temperature. After heat treatment, leading to crystallization of Sn-Y-O thin films, electrotransport process at room temperatures is thermally activated with an activation energy about 0.23 eV. After crystallization the Sn-Y-O films show hydrogen gas-sensitivity properties. Particularly, the injection of hydrogen into argon at 350°C leads to a more than 60 % decrease of electrical resistance for Sn-Y-O nanocrystalline thin film with Y concentration of 4.8 at. %.

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