Antiferromagnetic resonance AFMR

Apart from high applied field measurements, another powerful technique for the determination of the interaction fields is antiferromagnetic resonance (AFMR)253 255). Below the ordering temperature, the resonance frequency depends strongly on both HE and Ha according to the relation oily — (2HE HA)1/2 for HE > HA m is the applied frequency and y = ge/2mc is the magnetochemical ratio. 

The spin density wave (SDW) is a 2kF instability due to spin-spin interactions and the ground state has no lattice distortion. s is typical of an antiferromagnetic ground state and therefore anisotropic below the transition temperature, Tc. Antiferromagnetic resonance (AFMR) may be a good technique to characterize this transition. A particular characteristic is that the Tf1 NMR relaxation rate diverges at Tc. 

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