Imaging of c(8x2)/(4x6) GaAs(001) surface with noncontact atomic force microscopy -: art. no. 165419

Noncontact atomic force microscopy is used to study GaAs(001) surface having the c(8x2)/(4x6) reconstruction, which is often found for surfaces prepared at temperatures close to 900 K. Images taken with large tip-surface separations show hazy features, so-called ghosts X, aligned in chains parallel to the <(1) over bar 10 > direction and partially disordered but tending towards (x6) period along < 110 >. However, at lower tip-surface separation only a (4x1) pattern is clearly visible due to resolved surface atomic structure. The atomic-scale images are consistent with the recently proposed zeta model of c(8x2) reconstructed A(III)B(V) surfaces. Those findings indicate that the ghosts are visualized through modulation of the electric field only, and consequently they are of electronic but not structural origin.