X-ray powder spectroscopy to determine easy axis in colloidal magnetic particles
AbstractNon-interacting suspended colloidal single-domain magnetic particles can be expected to acquire a preferred orientation in a magnetic field. Their direction is determined by the easy magnetization axes of the particle and the applied field to a degree determined by the Langevin equation governing paramagnetic phenomena. The magnitudes of resulting changes in powder line intensities have been calculated and found to be of the order of 5 to 25% for ferrite particles near the critical size (where anisotropy energy kT), the larger for larger particles. The pattern of line intensity changes allows one to distinguish between (1,0,0) and (1,1,1) easy axes.