Antiferromagnetic domain formation and spin frustration induced by adjacent paired screw dislocations in 10 monolayer-thick Cr(001) films

Abstract

Abstract We investigated the growth and surface morphology of 10 monolayer (ML)-thick Cr(001) films on clean Au(001) surfaces. High quality epitaxial Cr(001) films with large atomically flat terraces and distinct surface states were successfully fabricated through growth at 300 K and subsequent post-annealing at 520 K. At 300 K, spin-polarized scanning tunneling microscopy images of both the topological and magnetic structures of this Cr film were obtained. The magnetic images exhibited the following features: (1) The layered antiferromagnetic (AF) order appeared in adjacent terraces and one ML-depth shallow hole in the terraces; (2) significant spin frustrations induced by adjacent paired screw dislocations caused the AF domain formation with 90 degrees quantum axis rotation and a large spin frustration area, not always limited in the vicinity of screw dislocations. The feature (2) was qualitatively reproduced by the micromagnetic simulation. These findings may be essential for the further development of spin-electronics utilizing thin AF films.