Temperature dependence of a resonance frequency of 59Co NMR in a ferromagnetic Heusler alloy Co2FeSi

The temperature dependence of the resonance frequency of 59Co NMR in a ferromagnetic Heusler alloy, Co2FeSi, in zero applied field is reported. The temperature dependence in the range 4.2–300 K has been found to be well described by ν=ν(0)(1-BT3/2)ν=ν(0)(1-BT3/2) with ν(0)=139.1MHz, and B=5.32×10-6K-3/2, which corresponds to the spin-wave stiffness constant D of 2.60 m eV nm2. The behavior is roughly in agreement with the temperature dependence of the macroscopic magnetization and is consistent with the dominance of the spin-wave excitations in Co2FeSi at low temperatures.

► The temperature dependence of the resonance frequency of 59Co is reported.
► The temperature dependence has been found to be well described by T3/2T3/2-law.
► The dominance of spin-wave excitations in Co2FeSi at low temperature was confirmed.
► The present results are in accord with macroscopic magnetization measurements.
► The present results are inconsistent with Brillouin light scattering experiments.