Magnetic microstructure in FePt (001) films with ultrahigh coercivity

抄録

Perpendicularly magnetized epitaxial FePt(001) films deposited on MgO (100) substrates have huge coercive forces of 48-54 kOe at room temperature for the thickness below about 300Å. The AFM images show that the films with high coercivity have a granular structure and are mainly composed of small particles below 0.3μm in diameter. The MFM images suggest that each domain contains one particle or some few particles coupled by exchange interactions. So, the domain can behaves as a single-domain. The coercivity depends on the particle size and the degree of epitaxial growth.