Excitation Spectrum of the Néel Ensemble of Antiferromagnetic Nanoparticles as Revealed in Mössbauer Spectroscopy

Figure 2

(a) Correlation between projections of the sublattice magnetization vectors and onto the easy axis for four normal precession modes of the vectors and of an ideal antiferromagnetic particle () and “uncompensated” antiferromagnetic particles () at . Branching points are indicated by the circles. (b) Four excitation branches for and three low-lying excitation branches (solid lines) in the energy spectrum of antiferromagnetic particles depending on the angle of deviation of the vector from the easy axis. The dotted line shows the energy relief for the corresponding ferromagnetic particle.