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arXiv · 0904.4194

Exchange stiffness in Co$_{2}$-based Heusler compounds

Jaroslav Hamrle·Oksana Gaier·Simon Trudel·Burkard Hillebrands·Horst Schneider·Gerhard Jakob
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Abstract

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 $D=715\pm20$ meV Å$^2$ ($A=31.5\pm1.0$ pJ/m) which is, to the best of our knowledge, only surpassed by the intermetallic compound Fe$_{53}$Co$_{47}$ (J. Appl. Phys. \textbf{75}, 7021 (1994)). Furthermore, we provide a systematization of the exchange stiffnesses determined for a variety of Co$_2$-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 L2$_1$ ordering increase. A qualitative explanation for the dependence on the valence electron concentration is provided.

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Jaroslav Hamrle, Oksana Gaier, Simon Trudel, Burkard Hillebrands, Horst Schneider, Gerhard Jakob. 2009-04-27. Exchange stiffness in Co$_{2}$-based Heusler compounds. https://arxiv.org/abs/0904.4194

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