Effect of magnetic field on stability and excitation spectrum of spin nanoclusters in anisotropic ferromagnetic chains
М.М. Bogdan1,2, V.I. Belan1, and О.V. Charkina1
1B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauky Ave., Kharkiv 61103, Ukraine
E-mail: bogdan@ilt.kharkov.ua; charkina@ilt.kharkov.ua
Received August 7, 2018, published online October 26, 2018
Abstract
The spectral problem of the internal mode oscillations of a spin nanocluster in an anisotropic ferromagnetic chain placed in a magnetic field has been solved exactly within the framework of the discrete Takeno–Homma model. A stability diagram on the plane of parameters of the exchange and the magnetic field is constructed for spin clusters of arbitrary sizes. Explicit expressions for the internal mode oscillations of nanoclusters are found and the frequency dependences on parameters of the exchange and the magnetic field are calculated.