Structure and magnetostriction of Sm1−xPrxFe2 and Sm0.9Pr0.1(Fe1−yBy)2 alloys

The structure, magnetostriction and anisotropy of Sm1-xPrxFe2 and Sm0.9Pr0.1(Fe1-yBy)(2) alloys have been investigated using X-ray diffraction, standard strain gauge technique and Mossbauer spectrum. It is found that the matrix of homogenized Sm1-xPrxFe2 alloys is the (Sm,Pr)Fe-2 phase with MgCu2-type cubic structure and the minor phases are (Sm,Pr)Fe-3 phase and rare earth-rich phase when x less than or equal to 0.3. When x = 0.4, the (Sm,Pr)Fe-3 phase is found to be the main phase and the minor phases become (Sm,Pr)Fe-2, (Sm,Pr)(2)Fe-17 and rare earth-rich phase. With further increasing Pr content, the amount of minor phases, (Sm,Pr)(2)Fe-17 and rare earth-rich phase increase, but that of (Sm,Pr)Fe-2 remains almost unchanged. For Sm0.9Pr0.1(Fe1-yBy)(2) alloys, the (Sm,Pr)(Fe,B)(2) as a matrix is up to y = 0.2, and the small amount of second phase is a rare earth-rich phase when y > 0.05. The manetostriction of Sm1-xPrxFe2 alloys exhibits a peak near x = 0.1 and that of Sm0.9Pr0.1(Fe1-yBy)(2) alloys decreases with increasing B content. The Mossbauer spectrum analysis shows that the easy axis of magnetization for Sm1-xPrxFe2 alloys lies in the direction up to x = 0.3 and the anisotropy of Sm1-xPrxFe2 alloys decreases with increasing Pr content. (C) 2002 Elsevier Science B.V. All rights reserved.