Low-energy-electron-diffraction determination of the atomic arrangement in a monatomic underlayer of nitrogen on Ti(0001)

The importance of recognizing a 1 × 1 structure preceding a superstructure in a chemisorption experiment is demonstrated by the system N-Ti(0001). Low-energy-electron-diffraction analysis of the 1 × 1 structure reveals that the N atoms are located in the octahedral holes 1.22±0.05 below the first layer of Ti atoms. Interatomic distances are such as to justify the view of the surface structure as a single double-layer of TiN. © 1976 The American Physical Society.