TY  - JOUR
AU  - Ewerlin, M.
AU  - Petracic, O.
AU  - Demirbas, D.
AU  - Agudo, L.
AU  - Eggeler, G.
AU  - Brüssing, F.
AU  - Abrudan, R.
AU  - Zabel, H.
TI  - Shift of the blocking temperature of Co nanoparticles by Cr capping
JO  - Journal of applied physics
VL  - 114
IS  - 23
SN  - 0021-8979
CY  - Melville, NY
PB  - American Inst. of Physics
M1  - FZJ-2015-03470
SP  - 233908
PY  - 2013
AB  - We have studied the effect of Cr capping on the magnetic properties of Co nanoparticles (NPs). The NPs have an average diameter of 2.2 nm. The blocking temperature T B of the bare Co particles is 13.2 K. By capping with a thin Cr layer up to a thickness of t Cr  = 0.52 nm, we first observe a decrease of T B up to t Cr  = 0.14 nm, followed by an increase of T B for larger thicknesses 0.14 nm ≤ t Cr ≤ 0.52 nm. X-ray magnetic circular dichroism measurements at the resonant Co and Cr L 3 edges confirm a magnetic polarization of Cr which is opposite to the magnetization of Co. The antiparallel alignment of Co and Cr spins at the Co/Cr interface can explain the decrease at low capping layer thickness. However, for larger Cr capping layer thicknesses, the Cr film bridges the Co NPs, mediating interparticle exchange coupling and enhancing dipolar coupling that leads to an increase of the blocking temperat
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000329056800034
DO  - DOI:10.1063/1.4851677
UR  - https://juser.fz-juelich.de/record/201165
ER  -