An influence of the Dzyaloshinskii-Moriya interaction on the magnetization reversal process of the finite-size Co chains on Pt(664) surface

Energy barriers for magnetization reversal of the finite-size Co chains on Pt(664) surface are calculated with taking the Dzyaloshinskii-Moriya interaction into account. For the numerical calculations the geodesic nudged elastic band method is employed. It has been found that the ground states of such atomic chains are noncollinear. The magnetization reversal of short atomic chains occurs without the formation of domain walls. At the same time, there are two nonequivalent ways for the magnetization reversal of longer atomic chains. The first way is the formation of clockwise domain wall (CDW) and the second way is the formation of anticlockwise domain wall (ACDW). The second way is energetically preferable. It is shown that a metastable state corresponding to the location of ACDW in the middle of the atomic chain can appear. The variation of the parameters of the Hamiltonian shows that the magnetization reversal via the CDW formation can occur only in a certain region of the parameters. The influence of the long-range dipole–dipole interaction on the energy barriers for the magnetization reversal is also investigated. It is shown that the most of the presented results can be satisfactory explained in the framework of the XY-model. The magnetic configurations of the atomic chain near the local minima and the saddle points can be approximated with simple analytical functions.