Density functional simulation of small Fe nanoparticles

We calculate from first principles the electronic structure, relaxation and magnetic moments of small Fe particles, by applying the numerical local orbitals method in combination with norm-conserving pseudopotentials. The accuracy of the method in describing elastic properties and magnetic phase diagrams is tested by comparing benchmark results for different phases of crystalline iron to those obtained by an allelectron method. Our calculations for the bipyramidal Fe5 cluster confirm previous plane-wave results that predicted a non-collinear magnetic structure. For larger bcc-related (Fe35, Fe59) and fcc-related (Fe38, Fe43, Fe55, Fe62) particles, a larger inward relaxation of outer shells has been found in all cases, accompanied by an increase of local magnetic moments on the surface to beyond 3μB. PACS. 36.40.Cg Electronic and magnetic properties of clusters – 75.50.Bb Fe and its alloys – 71.15.-m Methods of electronic structure calculations