We determine the spin wave exchange stiffness D and the exchange constant A for the full Heusler compound \CFS using Brillouin light scattering spectroscopy. We find an extraordinarily large value of D=715±20 meV \AA2 (A=31.5±1.0 pJ/m) which is, to the best of our knowledge, only surpassed by the intermetallic compound Fe53Co47 (J. Appl. Phys. \textbf{75}, 7021 (1994)). Furthermore, we provide a systematization of the exchange stiffnesses determined for a variety of Co2-based Heusler compounds. We find that for the investigated compounds, the exchange stiffness is a function of the valence electron concentration and the crystallographic ordering. The exchange stiffness increases when the valence electron concentration and/or the amount of the L21 ordering increase. A qualitative explanation for the dependence on the valence electron concentration is provided.
@article{arxiv.0904.4194,
title = {Exchange stiffness in Co$_{2}$-based Heusler compounds},
author = {Jaroslav Hamrle and Oksana Gaier and Simon Trudel and Burkard Hillebrands and Horst Schneider and Gerhard Jakob},
journal= {arXiv preprint arXiv:0904.4194},
year = {2009}
}