HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY STUDY OF NANOSCALE NI-RICH NIAL FILMS EVAPORATED ONTO NACL AND KCL

The atomic and microstructure of Ni-rich B2 NixAl100-x thin films with nanoscale dimensions,for thickness as well as lateral grain size, and produced by evaporation onto NaCl and KCl (001) surfaces are investig ated by high resolution electron microscopy. Different textures and or ientation relationships with the substrate are found exhibiting grains with [001], [011] and [111] zones parallel with the film normal. Loca l distortions including precursor-like domains and surface shearing as well as dislocations are observed in the grains. No micromodulations as in bulk martensite precursors are visible. No martensitic transform ation was observed when cooling the free standing films to -170 degree s C. (C) 1998 Acta Metallurgica Inc.