%0 Journal Article
%T Inelastic neutron scattering study of crystal field excitations of Nd3+ in NdFeAsO
%A Y. Xiao
%A M. Zbiri
%A R. A. Downie
%A J. -W. G. Bos
%A Th. Brueckel
%A T. Chatterji
%J Physics
%D 2013
%I arXiv
%R 10.1103/PhysRevB.88.214419
%X Inelastic neutron scattering experiments were performed to investigate the crystalline electric field (CEF) excitations of Nd3+ (J = 9/2) in the iron pnictide NdFeAsO. The crystal field level structures for both the high-temperature paramagnetic phase and the low-temperature antiferromagnetic phase of NdFeAsO are constructed. The variation of CEF excitations of Nd3+ reflects not only the change of local symmetry but also the change of magnetic ordered state of the Fe sublattice. By analyzing the crystal field interaction with a crystal field Hamiltonian, the crystal field parameters are obtained. It was found that the sign of the fourth and sixth-order crystal field parameters change upon the magnetic phase transition at 140 K, which may be due to the variation of exchange interactions between the 4f and conduction electrons.
%U http://arxiv.org/abs/1309.7323v1