Computational studies for the interpretation of gas response of SnO2(110) surface

Tin dioxide is a widely used material in gas sensing applications. This is partly due to its stable surface structure and high sensitivity to many gas es. The interaction of different gas components with an oxide surface may l ead to changes in the lattice oxygen content at the surface in addition to changes in the amount of adsorbed species. The electronic and atomic struct ures of the surface change with the changes in the lattice oxygen content. This leads to surface relaxation and changes in the surface dipole layer of the ionic surface in addition to changes in the Schottky barrier which is a result of the charge accumulation onto the surface from the bulk of the s emiconducting oxide. Changes in both the dipole layer and the Schottky barr ier change the work function of the semiconductor and may reflect in its el ectrical conductivity. Here we have used first-principles calculations base d on LDA-SCF to study changes in the electronic and atomic structures of th e SnO2(110) surface as a result of oxygen exchange between the lattice and the ambient gas. The transducer function relating the changes at the surfac e to the changes in the conductivity of a ceramic microstructure is also de scribed by an example. (C) 2000 Elsevier Science B.V. All rights reserved.