We have studied the segregation of potassium to the surface of TiO2(100) using Auger electron spectroscopy (AES), low energy electron diffraction (LEED), direct recoil spectroscopy (DRS), and mass-spectroscopy of recoiled ions (MSRI). It is found that the concentration of potassium at the surface is strongly influenced by hte sample temperature. MSRI results indicate the presence of potassium starting at annealing temperatures of 675 K and the subsequent disappearance above 875 K. Conversely, AES only indicates the presence of potassium after annealing the sample to 975 K. Together these results indicate that below 875 K, potassium exists in the very topmost surface layer, while above 875 K, potassium is located below this layer.
Revised: November 11, 2002 |
Published: June 1, 1999
Citation
Herman G.S., and C.H. Peden. 1999.Segregation of K at the TiO2(100) Surface.Colloids and Surfaces. A, Physicochemical and Engineering Aspects 154, no. *-2:187-192.PNNL-SA-30189.