STM CHARACTERIZATION OF A C(2X2) RECONSTRUCTION ON NA0.65WO3(100)

A c(2 X 2) reconstruction on the (100) surface of the perovskite sodiu m-tungsten-bronze Na0.65WO3 has been characterised by atomically resol ved scanning tunnelling microscopy. The reconstruction is formed by an nealing crystals in UHV at temperatures above 650 degrees C and probab ly involves termination of a WO2 surface layer with an O-0.5 adlayer t hat completes the six-fold coordination of half the surface W ions. Su rfaces can be imaged in STM under a wide range of bias conditions prob ing both filled and empty electronic states.