Comparative studies of magnetic properties of Co films on annealed and unannealed rubrene/Si(100)

Structural and magnetic properties of cobalt nanostructures on SiO 2 /Si(1 1 1) substrates

“…For annealed Co/SiO 2 /Si(1 1 1) films submitted to hydrogen plasma, we observe an enhancement of the coercive field, regarding to the as deposited and annealed films, which could be related to the formation of Co islands in triangular shapes. Similar behavior has been reported for Co deposited onto annealed rubrene/Si(1 0 0) [15]; the observed enhancement of the squareness of magnetization curve for Co overlayer was attributed to formation of Co islands in triangular shapes.…”

“…Various synthesis approaches based on physical or chemical vapor depositions are employed. For instance, when deposited on annealed rubrene/Si(1 0 0), cobalt was found to form islands in triangular shapes [15]. Because of the clustering and pinhole formation for annealed rubrene layer, the formation of a Co/Si(1 0 0) interface was found to be crucial for the occurrence of pyramid-like nanostructures with an hcp stacking of the Co layer.…”

Lithography-free synthesis of nanostructured cobalt on Si (111) surfaces: structural and magnetic properties

“…For annealed Co/Si(111) films submitted to hydrogen plasma, we observe an enhancement of the coercive field, compared to the as deposited and annealed films, which could be related to the formation of Co islands in triangular shapes. Similar behavior has been reported for Co deposited on annealed rubrene/Si(100) [14]; the observed enhancement of the squareness of magnetization curve for Co overlayers was attributed to formation of Co islands in triangular shapes.…”

“…It is to notice that increasing the plasma treatment from 20 minutes to 1 hour does not modify the measured hysteresis loop. The formation of Co islands in triangular shapes was found to play an important role on the enhancement of the squareness of magnetization curve of Co deposited on annealed rubrene/Si(100) [14]. In order to qualitatively describe the magnetization behavior, numerical simulations have been performed using the OOMMF software to find equilibrium magnetization distributions for different external magnetic fields: the 2D solver was utilized with a cell size of 5 nm and the usual Co bulk material parameters: saturation magnetization M s = 1400×10 3 A/m (1400 emu/cm 3 ), exchange constant A = 13×10 -12 J/m (1.3×10 -6 erg/cm).…”

“…These silicides have been extensively studied because of their excellent electrical properties (Schottky barrier and high mean free path of electrons). Cobalt deposited on annealed rubrene/Si(100) forms Co islands in triangular shapes [14]. Because of the clustering and pinhole formation for annealed rubrene layer, the formation of a Co/Si(100) interface was found to be crucial for the occurrence of the pyramid-like nanostructure with an hcp stacking of the Co layer.…”