TY  - JOUR
AU  - Peters, L.
AU  - Di Marco, I.
AU  - Grånäs, O.
AU  - Şaşıoğlu, E.
AU  - Altun, A.
AU  - Rossen, S.
AU  - Friedrich, Christoph
AU  - Blügel, S.
AU  - Katsnelson, M. I.
AU  - Kirilyuk, A.
AU  - Eriksson, O.
TI  - Correlation effects and orbital magnetism of Co clusters
JO  - Physical review / B
VL  - 93
IS  - 22
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2017-03341
SP  - 224428
PY  - 2016
AB  - Recent experiments on isolated Co clusters have shown huge orbital magnetic moments in comparison with their bulk and surface counterparts. These clusters hence provide the unique possibility to study the evolution of the orbital magnetic moment with respect to the cluster size and how competing interactions contribute to the quenching of orbital magnetism. We investigate here different theoretical methods to calculate the spin and orbital moments of Co clusters, and assess the performances of the methods in comparison with experiments. It is shown that density-functional theory in conventional local density or generalized gradient approximations, or even with a hybrid functional, severely underestimates the orbital moment. As natural extensions/corrections, we considered the orbital polarization correction, the LDA+U approximation as well as the LDA+DMFT method. Our theory shows that of the considered methods, only the LDA+DMFT method provides orbital moments in agreement with experiment, thus emphasizing the importance of dynamic correlations effects for determining fundamental magnetic properties of magnets in the nanosize regime.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000378811500006
DO  - DOI:10.1103/PhysRevB.93.224428
UR  - https://juser.fz-juelich.de/record/829697
ER  -