LAUSR

Abstract Co, Ni, Co55Fe45 and Co40Fe40B20 layers were grown on Pb0.71Sn0.29Te (111) crystalline topological insulator films by conventional and laser molecular beam epitaxy (LMBE) methods. It was demonstrated that the Co40Fe40B20 ferromagnetic films were grown epitaxially on the crystalline topological insulator surface, with clear epitaxial relations. Obtained Co40Fe40B20 layers have a bcc crystal structure with a crystalline (111) plane parallel to the (111) plane of Pb0.71Sn0.29Te. The use of reciprocal space three-dimensional mapping of reflection high electron diffraction (RHEED) patterns made it possible to determine the epitaxial relations of the film and substrate. Using laser based angle-resolved photoemission spectroscopy (LARPES) the clean Pb0.71Sn0.29Te surface with Dirac-like dispersion of the topological surface states was demonstrated. The stable surface topological state of Pb0.71Sn0.29Te was observed at least at the monolayer thick Co coverage. It was shown that Co (or Ni) and Co55Fe45 may be used as a pair of contacts (injector and detector) with different coercivities for spin transport measurements in the “metal – topological insulator” systems. The measurements of magnetic and transport properties show distinct hysteresis – type dependence of the magnetoresistance in the range of quadratic I(U) dependence.