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 similar to 140 K, which may be due to the variation of exchange interactions between the 4f and conduction electrons.
|Number of pages||6|
|Journal||Physical Review B: Condensed Matter and Materials Physics|
|Publication status||Published - 1 Dec 2013|
- LAYERED QUATERNARY COMPOUND
- CONDUCTION ELECTRONS
- COULOMBIC PART