Anisotropy in Epitaxial Films.
Abstract
Experiments on epitaxial Ni films grown on epitaxial Cu films grown on single crystal (100) Si wafers in a molecular beam epitaxy system modified to make in situ magneto-optic Kerr effect (MOKE) measurements were carried out. Ex situ transmission electron microscopy and wafer curvature measurements were made and it was shown that the onset of misfit accommodation, the decrease in Ni strain with increasing film thickness, and the increase in misfit dislocation density were consistent with existing models for misfit accommodation. In situ MOKE studies and ex situ vibrating sample magnetometry studies of the magnetic consequences of the changing strain with Ni film thickness showed that the magnetic easy axis of the Ni/Cu(001) films was perpendicular to the film plane over the range 1.5 to approximately 6 nm. We have found from these studies that the low-thickness transition from perpendicular to in-plane magnetization with decreasing film thickness (seen also in ultra-thin Fe/Cu and Fe/Ag) is NOT associated with the critical thickness leading to the onset of MD formation, but results instead from a complex interplay of magnetostatic and magnetoelastic energies, and of the Neel magnetic surface anisotropy as well as the surface magneto-elastic anisotropy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 13, 1997
- Accession Number
- ADA328297
Entities
People
- Carl V. Thompson
- R. C. O'handley
Organizations
- Massachusetts Institute of Technology