Abstract
The structure, Curie temperature and magnetostriction of Pr x Dy 1-x Fe 2 (0⩽x⩽0.5) and Pr 0.4 Dy 0.6 (Fe 1-y M y ) 2 (0⩽y⩽0.6) alloys (M=Co, Ni) have been investigated using optical microscopy,x-ray diffraction,ac initial susceptibility and standard strain gauge techniques. The matrix of homogenized Pr x Dy 1-x Fe 2 alloys is a cubic Laves phase (Pr, Dy)Fe 2 with MgCu 2 -type structure, with a small amount of second phase (Pr, Dy)Fe 3 when x⩽0.2. The amount of (Pr, Dy)Fe 3 phase increases with the increase of Pr content, and it becomes the main phase when x=0.4. When x=0.5, the matrix is found to be the (Pr, Dy) 2 Fe 17 phase coexisting with a small amount of phases (Pr, Dy)Fe 2 , (Pr, Dy)Fe 3 and rare-earth rich phases. For Pr 0.4 Dy 0.6 (Fe 1-y Co y ) 2 alloys, the amount of (Pr, Dy)(Fe, Co) 2 phase increases with increasing Co content and the phase (Pr, Dy)(Fe, Co) 2 becomes the main phase when y=0.6. However, the substitution of Ni for Fe up to 60 at % Ni in Pr 0.4 Dy 0.6 Fe 2 alloys does not favor the formation of the cubic Laves phase (Pr, Dy)(Fe, Ni) 2 . The lattice constant of Pr x Dy 1-x Fe 2 alloys decreases with increasing x, whereas the Curie temperatureT c increases. The magnetostriction of Pr x Dy 1-x Fe 2 alloys at room temperature exhibits a peak at x=0.3. The lattice constant of Dy 0.6 Pr 0.4 (Fe 1-y Co y ) 2 alloys decreases slowly with increasing y; T c shows a peak when y=0.45, and the room temperature magnetostriction becomes negative when x>0.45. The Curie temperature of Dy 0.6 Pr 0.4 (Fe 1-y Ni y ) 2 alloys decreses with the increase of Ni content. The room temperature magnetostriction of Dy 0.6 Pr 0.4 (Fe 1-y Ni y ) 2 also becomes negative when x>0.45
Original language | English |
---|---|
Pages (from-to) | 2805-2809 |
Number of pages | 5 |
Journal | Journal of Applied Physics |
Volume | 85 |
Issue number | 5 |
Publication status | Published - 1 Jan 1999 |