TIP INDUCED CHANGES OF ATOMIC-SCALE IMAGES OF THE VANADIUMPENTOXIDE SURFACE

We have measured atomic resolution scanning tunnelling microscopy imag es of V2O5. The layered compound V2O5 is a strongly anisotropic materi al with the layers parallel to the (ab) plane. Although V2O5 is a semi conductor with an optical gap of 2.3 eV an impurity band allows STM me asurements with a good signal to noise ratio. Here we present atomic s cale images of the V2O5 surfaces. The images show the periodicity of t he bulk unit cell, but we observe various surface modifications, which transform into each other during scanning of the surface.