SURFACE POLYTYPIC DETERMINATION OF NIOBIUM DISELENIDE BY RHEED

Convergent beam RHEED measurements and calculations made on MoS2 have been extended to azimuthal rocking curve measurements on another membe r of the layered transition metal dichalcogenide family, NbSe2. These results, obtained in a dedicated RHEED apparatus at Nagoya University, show in comparison with other materials (e.g. Si, Ag) more rapidly va rying structure oscillations, due to the large unit cell in the c-axis direction normal to the crystal surface. The observed structure provi des the basis for polytype structure determination close to the surfac e.