A summary is presented of a low-energy electron diffraction study of the Si(111) 7 multiplied by 7 to ″1 multiplied by 1″ transitions. Excess diffuse scattering appears during the transition and demonstrates that the transition is to a disordered selvedge at high temperatures. The long-range order shows critical behavior for reduced temperature between 0. 93 and 0. 99 with a critical exponent beta equals 0. 11 plus or minus 0. 15 which is similar to values for 2d Ising and Potts models but distinctly different from the meanfield values. Critical scattering with properties similar to those for mean-field or 2d Ising models is not observed. The relaxation time for ordering diverges near T//c but the disordering kinetics remain faster than the experimental time constant of . 05 s.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of vacuum science & technology|
|State||Published - 1980|
|Event||Proc of the Natl Symp of the Am Vac Soc, 27th, Pt 2 - Detroit, MI, Engl|
Duration: Oct 13 1980 → Oct 17 1980
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