METALLABORANES AS MOLECULAR PRECURSORS TO THIN METAL BORIDE FILMS - CONVERSION OF HFE3(CO)9BH4 TO AMORPHOUS FE75B25

The thermal decomposition of HFe3(CO)9BH4 on glass or aluminum substrates at 175-200 °C at pressures between 10−5 and 10−4 Torr results in the deposition of uniform, amorphous alloy films of approximate composition Fe75B26 with individual film thicknesses ranging from 1000 to 10000 Å. The glassy metal films have been characterized by Auger, X-ray, and Mössbauer spectroscopies. The Mössbauer spectra show that the local structure of the film is similar to that observed for films prepared by rapid quenching techniques. In contrast, magnetically ordered films prepared from HFe3(CO)9BH4 exhibit magnetic moments having a preferential orientation normal to rather than parallel with the film plane. Although the films are stable in air, oxidation during deposition readily takes place under poor vacuum conditions and leads to films containing oxidized boron. The stoichiometry of the oxide phase has been shown to be B2O3 (oxygen content 3-11%). The film resistivity increases with increasing oxygen content. © 1990, American Chemical Society. All rights reserved.