Abstract
Helium atom scattering experiments have been carried out on the (001) surface of KTaO3 doped
with 6, 10 and 15% Nb, produced by cleaving in situ single crystal samples. Several phenomena were
observed through He atom di raction measurements, including metastable behavior immediately
after cleaving, reconstruction of a fraction of the surface to (21) domains after thermally cycling
the surface temperatures, and the distribution of step-heights of terraces at the surface as multiples
of the unit cell dimension of 4 A. In addition, a large hysteresis e ect was found in the in the
<100> azimuth in the variation of surface re
ectivity with surface temperature; a much smaller
hysteresis e ect was found in the <110> azimuth. The hysteresis e ects appear for all Nb doping
concentrations. Finally, small oscillations in the specular and Bragg di raction intensities near
surface temperature 80K were also observed.