MAGNETIC-ANISOTROPY IN ARRAYS OF NANOMETER-SCALE IRON PARTICLES

Arrays of ferromagnetic iron particles have been fabricated by a combi nation of chemical vapor deposition and scanning tunneling microscopy. Hall magnetometry and MFM measurements have been used to determine th eir magnetic properties. The measured switching fields indicate magnet ization reversal by curling from which an exchange length, lambda(ex) = 3.1 nm, may be estimated. The cylindrically shaped particles have an easy magnetization direction (EMD) along their long axis due to shape anisotropy. The magnetic anisotropy is evaluated by fitting calculate d magnetization curves to those measured with applied field perpendicu lar to the particles EMD.