The feasibility of detecting magnetic excitations using monochromated electron energy loss spectroscopy in the transmission electron microscope is examined. Inelastic scattering cross-sections are derived using a semi-classical electrodynamic model, and applied to AC magnetic susceptibility measurements and magnon characterization. Consideration is given to electron probes with a magnetic moment, such as vortex beams, where additional inelastic scattering can take place due to the change in magnetic potential energy of the incident electron in a non-uniform magnetic field. This so-called ‘Stern-Gerlach’ energy loss can be used to enhance the strength of the scattering by increasing the orbital angular momentum of the vortex beam, and enables separation of magnetic from non-magnetic (i.e. dielectric) energy losses, thus providing a promising experimental route for detecting magnons. AC magnetic susceptibility measurements are however not feasible using Stern-Gerlach energy losses for a vortex beam.

检查在透射电子显微镜中使用单色电子能量损失光谱检测磁激发的可行性。非弹性散射截面是使用半经典电动力学模型导出的，并应用于交流磁化率测量和磁振子表征。考虑了具有磁矩的电子探针，例如涡旋束，其中由于非均匀磁场中入射电子的磁势能的变化，可能会发生额外的非弹性散射。这种所谓的“Stern-Gerlach”能量损失可用于通过增加涡旋光束的轨道角动量来增强散射强度，并使磁性与非磁性（即介电）能量损失分离，从而为检测磁振子提供了一条有前途的实验途径。然而，使用涡旋光束的 Stern-Gerlach 能量损失进行交流磁化率测量是不可行的。