L. Schnelzer, O. Waldmann, M. Horvatić, S. T. Ochsenbein, S. Krämer, C. Berthier, H. U. Güdel and B. Pilawa
Huge Transverse Magnetic Polarization in the Field-Induced Phase of the Antiferromagnetic Molecular Wheel CsFe₈
Phys. Rev. Lett. 99, 087201/1-4 (2007)                 

Abstract: The ¹H NMR spectrum and nuclear relaxation rate T^–1₁ in the antiferromagnetic wheel CsFe₈ were measured to characterize the previously observed magnetic field-induced low-temperature phase around the level crossing at 8 T. The data show that the phase is characterized by a huge staggered transverse polarization of the electronic Fe spins, and the opening of a gap, providing microscopic evidence for the interpretation of the phase as a field-induced magnetoelastic instability.