Magnetic properties of Fe thin films on Ag submicrometer islands

Abstract

Face-centered-cubic Ag(100) submicrometer islands on an RCA-cleaned Si(100) substrate were fabricated by molecular beam epitaxy; a 500 Å Fe thin film was then grown onto Ag films at 100 °C. We experimentally demonstrate that the magnetic behavior of Fe films is strongly dependent on the thickness and morphology of the Ag underlayer. The Ag film, in order to reduce the surface free energy, forms isolated three-dimensional square islands with {111} sidewall on the Si(100) substrate. The average height, grain size and surface roughness of these Ag islands were tuned by varying the deposition thickness of the Ag film. The in-plane easy axis of the Fe film was rotated 45° while the thickness of the Ag underlayer reaches 100 Å and the Ag rough surface provides a source of domain wall pinning.

The magnetization reversal of Fe films on Ag submicrometer pyramidal islands

“…The Ag layer was then deposited on the Si(100) substrate at 500 C by a Kundsen cell with a deposition rate of around 0.05 Å/s in an Eiko EL-10A molecular-beam epitaxy (MBE) deposition system. The same as previous reports [10], Ag films formed face-centered cubic (fcc) (100) structure on Si(100) substrates with a 4:3 coincidence growth. From reflection high-energy electron diffraction (RHEED) [10], we determined the crystal relationship between Ag and Si, that is, .…”

“…The same as previous reports [10], Ag films formed face-centered cubic (fcc) (100) structure on Si(100) substrates with a 4:3 coincidence growth. From reflection high-energy electron diffraction (RHEED) [10], we determined the crystal relationship between Ag and Si, that is, . The investigation of atomic force microscopy (AFM) showed that the Ag films formed square-like islands with island edges parallel to in-plane directions, as shown in Fig.…”

“…It shows that the Fe film grown on Ag pyramidal islands has perpendicular hysteresis behavior. Note that Fe films were almost magnetically isotropic in the film plane [10].…”

“…As our expectation, the morphology of Fe films followed the shape of underlying Ag pyramidal islands. From the previous investigation [10] on the top surface of Ag pyramidal islands, rotates an angle of 45 to match the underlying Ag lattice as reported by other groups [11]. The hysteresis loops of Fe films were measured by a vibration sample magnetometer.…”

“…From the above investigations, the Ag films formed submicrometer pyramidal islands with a (100) truncated top and four (111) sidewalls on Si(100) substrates. More detailed investigation of RHEED and AFM can be found in [10].…”