Tkachenko V. The influence of the interface magnetic inhomogeneities on the propagation of spin waves in magnonic crystals

The Ph.D. thesis is devoted to the study of processes of propagation characteristics of spin waves in magnetic nanostructures. The main objective of this thesis is the study of the propagation , reflection and transmission of spin waves in materials that can be represented as a periodic structure with modulated magnetic parameters as well as the study spin wave propagation and trannsmission processes in curved magnetic systems. The influence of interface inhomogeneity of such structures on the spectrum of spin waves and reflections is also cosidered in the thesis. The following main results were obtained: spectrum of spin waves for magnon crystals with finite thickness of the interface was obtained for different interface profiles, several models such as a linear distribution of magnetic anisotropy in the interface, disrtribution proportional to cosine and elliptic sine were compared; analitical expression for spin wave spectrum in curved nanowire was obtained; the processes of reflection and transmision of spin waves were studied for the case of planar magnon crystal and for the case of curved magnetic nanowire. The results of the thesis can be used in carrying out relevant research institutes in the NAS and higher educational institutions of Ukraine.