| [001] surfaces of P4W8O32 obtained by cleavage in UHV are analyzed at room temperature by UPS, LEED and STM. Two types of facets are revealed. The type I shows periodic parameters very close to the parameters of the bulk unit cell. It corresponds to a relaxed (1x1) surface, and the surface defects may produce a (3x1) reconstruction. The type II facets show a periodicity of 7.45 Å, that is the distance between two second neighboring tungsten sites and corresponds to facets parallel (001)p, the dense planes of the perovskite-like WO3 slabs. This parameter reflects also the width of the steps ending the WO3. |
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