Zakeri Lori, K., Zhang, Yu, Kirschner, J.
Surface magnons probed by spin-polarized electron energy loss spectroscopy
Journal of Electron Spectroscopy and Related Phenomena 189, pp 157-163 (2013)
Short-wavelength magnons at ferromagnetic surfaces can be probed by electrons. The unique property of electrons, i.e. having a very strong interaction with the surface together with the spin degree of freedom enables one to investigate the spin dependent quasi-particles, e.g. magnons at magnetic surfaces.
We review the experimental results of short-wavelength magnons probed at ferromagnetic Co(0001) and Fe(110) surfaces by spin-polarized electron energy-loss spectroscopy. The differences and similarities to their bulk counterpart are discussed in detail. Although in the case of Co(0001) surface magnons behave similar to the ones in bulk Co, in the case of Fe(110) they possess a smaller exchange stiffness meaning that the effective exchange coupling is smaller at the surface. In both cases, surface magnons have an extremely short lifetime being in the order of a few tens of femtosecond.