Abstract
Abstract A finite-size ferromagnetic chain of classical XY spins, where each of the two edge spins is exchange-coupled to a fictitious fully-pinned spin, is investigated in the presence of a weak in-plane perturbation (external magnetic field or uniaxial anisotropy). Within a macrospin approximation, the above chain model can be representative of a soft ferromagnetic film consisting of N parallel atomic layers, sandwiched between two magnetically hard films. In zero field, the model has a ferromagnetic collinear ground state and admits a class of metastable helical states containing an integer number of twists. Analytical expressions are obtained for the linear corrections to the helical magnetic configuration and for the local magnetic susceptibility tensor. The dependence of the integral susceptibility of the chain, χ , on the number of spins in the chain, N, is also calculated. It is found that χ ∝ N 3 for small values of the helix mode ( m ≪ N ), while χ ∝ N 2 for large values of the helix mode ( m ≈ N + 1 4 ).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.