O. Waldmann, T. C. Stamatatos, G. Christou, H. U. Güdel, I. Sheikin and H. Mutka
Quantum Phase Interference and Néel-Vector Tunneling in Antiferromagnetic Molecular Wheels
Phys. Rev. Lett. 102, 157202/1-4 (2009)                 

Abstract: The antiferromagnetic molecular wheel Fe₁₈ of 18 exchange-coupled Fe^III ions has been studied by magnetic torque, magnetization, and inelastic neutron scattering. The combined data show that the low-temperature magnetism of Fe₁₈ is very accurately described by the Néel-vector tunneling (NVT) scenario, as unfolded by semiclassical theory. In addition, the magnetic torque as a function of applied field exhibits oscillations that reflect the oscillations in the NVT splitting with field due to quantum phase interference.