Surface structures on sputtered/annealed WC(0001)

We use scanning tunnelling microscopy, Auger electron spectroscopy and low energy electron diffraction to study different tungsten and carbon terminat ed surface reconstructions on the sputtered/annealed WC(0001) surface. The tungsten terminated surface encompasses a (root 7 x root 7)R19 degrees W-tr imer structure, a (root 3 x root 7) reconstruction representing a transitio n structure from the (root 7 x root 7)R19 degrees reconstruction to a (6 x 1) phase which consists of a quadratic W overlayer on the first close-packe d carbidic carbon layer. The carbon terminated WC(0001) surface consists of a single graphitic carbon layer on top of the (6 x 1) structure.