Localized spin modes in ferromagnetic cylindrical dots with in-plane magnetization

A study of spin localized excitations in ferromagnetic tangentially magnetized dots of cylindrical shape and of nanometric size is presented. A recently formulated variational theory permits us to study the most representive localized spin modes of the spectrum. One of these, the fundamental mode, is mainly localized in the central part of the dot endfaces and represents the analogous in nonellipsoidal samples of the Kittel uniform mode in ellipsoids. We also investigate the dynamical properties of spin modes localized in the lateral part of the dot endfaces along the direction of the applied magnetic field studying the dependence of their localization from the variational parameter and from the applied magnetic field. Finally, a comparison of the calculated frequencies of some of these localized modes with available experimental data is performed.