F.c.c. type-III antiferromagnetism in YbN

Neutron diffraction experiments performed for YbN in the temperature range from 7 mK to room temperature prove the existence of long-range f.c.c. antiferromagnetic ordering of type III belowT _N =(0.790±0.005) K. The low ordered magnetic moment of Yb at saturation, =(0.39±0.05)> _B , is presumably caused by Kondo hybridization. By means of inelastic neutron scattering the crystalfield level scheme was established to be ₆ – ₈(33 meV)– ₇(81 meV). The ₆ – ₈ transition was found to be split into two lines which may be due to a bound state between the crystal-field excitation and phonons.