Rapidly solidified (FePt)_(70)P_(30) alloy with high coercivity

摘要

The alloy Fe_(35)Pt_(35)P_(30), whose composition is close to a ternary eutectic, was rapidly solidified by melt spinning and the ribbon exhibited a high coercivity, exceeding 20 kOe after annealing. The alloy was mainly composed of Ll_(0) ordered FePt and PtP_(2) with an average grain size of about 50 nm. In the as-cast state, the alloy was comprised of about 20-nm-diam FePt and PtP_(2) grains supersaturated with P and Fe, respectively, and the coercivity was only 150 Oe. The high coercivity obtained following annealing is discussed on the basis of the microstructural observations.