Ribbons of nominal composition (Pr_(9.5)Fe_(84.5)B _6)_(0.96)Cr_(0.01)(TiC)_(0.03) were produced by arc-melting and melt-spinning the alloys on a Cu wheel. X-ray diffraction (XRD) reveals two main phases, one based upon α-Fe and the other upon Pr_2Fe_(14)B. The ribbons show exchange spring behavior with H _c = 12.5 kOe and (BH)_(max) = 13.6 MGOe when these two phases are well coupled. Transmission electron microscopy revealed the coupled behavior is observed when the microstructure consists predominantly of α-Fe grains (diameter ~100 nm.) surrounded by hard material containing Pr_2Fe_(14)B. The microstructure is discussed in terms of a calculation by Skomski and Coey. A first-order-reversal-curve (FORC) analysis was performed for both a well-coupled sample and a poorly coupled sample. The FORC diagrams show two strong peaks for both the poorly coupled sample and for the well-coupled material. In both cases, the localization of the FORC probability suggests magnetizing interactions between particles. Switching field distributions were calculated and are consistent with the sample microstructure.
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