TECHNICAL MAGNETIC-PROPERTIES OF MELT-SPUN (ND1-XPRX)(2)FE14B AT LOW-TEMPERATURE

The spin-reorientation temperatures T-s and technical magnetic propert ies (coercivity H-ei and energy product (BH)(max)) of isotropic and al igned compacts of the pseudoternary melt-spun compound (Nd1-xPrx)Fe14B (0 less than or equal to x less than or equal to 0.52) have been stud ied as a function of temperature for 10 K less than or equal to T less than or equal to 150 K. Results measured on thermomechanically proces sed ('die-upset') samples are included for comparative purposes. Latti ce parameters were measured with transmission synchrotron X-ray diffra ction to verify the nominal compositions, and grain size determined by peak-broadening confirmed that these materials are nanoscaled. The sp in-reorientation temperatures decrease with increasing x and are Found to be significantly lower than their bulk-literature counterparts. Bo th the coercivity and the energy product of the isotropic compacts dec rease with increasing temperature; no anomaly in either property is fo und at T-s. The relative decrease in a technical magnetic property fro m its value at 10 K becomes smaller with increased Pr-content. The sub stitution of only a few atomic percent of Pr for Nd causes the coerciv ity to decrease sharply from its Pr-free value; the coercivity gradual ly recovers as increasing amounts of Pr art substituted into the latti ce. (C) 1997 Elsevier Science B.V. All rights reserved.