Nanoscale modifications of chalcogenide glasses using scanning tunneling microscopes

Nanoscale modifications in Cu-As-Se glasses (less than or equal to30 Cu at. %) produced by a scanning tunneling microscope have been studied comparatively with those in As2Te3 and Ag35As26Se39 glasses and in Ag and Cu3AsSe4 crystals. When subjected to the tip voltages greater than +/-3 V, all the samples, except Cu-As-Se glasses, produce hillocks or holes. In the Cu-As-Se glasses, nanometer hills accompanying peripheral grooves appear upon applications of negative tip voltage of about -5 V for 1 s. The size increases if the voltage is applied with light illumination, but it does not depend upon temperature (20-100degreesC) at which the voltage is applied. The size also increases in the glasses with higher Cu contents. This deformation can be accounted for as a Taylor cone produced under electronically induced fluidity. (C) 2002 American Institute of Physics.