STRAIN RELAXATION IN FE-3(AL,SI) GAAS - AN X-RAY-SCATTERING STUDY/

Lattice strain of epitaxially grown single crystal Fe-3(Al,Si)/GaAs fi lms was measured in a synchrotron x-ray scattering experiment. The Fe3 Al film (2.5% lattice mismatch) was partially strained and tetragonall y distorted at room temperature. As the sample was annealed to 500 deg rees C, the internal strain was mostly relaxed while the tegragonal di stortion was greatly reduced. We believe that the strain relaxation wa s caused by the interdiffusion of atoms through domain boundaries at e levated temperatures. In comparison, the Fe3Si film with much less lat tice mismatch (0.17%) was completely strained up to 600 degrees C with out being relaxed. (C) 1996 American Institute of Physics.