Magnetism and crystal chemistry in REFe sub 12 minus x Ga sub x (RE=Y,Ce,Pr,Nd,Sm,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu and MM=mischmetal) and (Zr,Pr) (Fe sub 1 minus x Co sub x ) sub 12 minus y Ga sub y
- Institute of Physical Chemistry, University of Vienna, A-1090 Wien, Waehringerstrasse 42 (Austria)
The existence of ternary compounds according to the formula REFe{sub 12{minus}{ital x}} Ga{sub {ital x}} which for {ital x} {approximately}6 represents the iron-rich end of a homogeneous range has been confirmed. X-ray powder analysis of alloys annealed at 800 {degree}C or above generally reveal isotypism with the body- centered tetragonal ThMn{sub 12} -type structure. For the alloys with heavier rare-earth elements from Gd to Lu a phase transition to a body-centered orthorhombic structure type (ScFe{sub 6} Ga{sub 6} type) is observed, which has not been reported before. The transition corresponds to a crystallographic group-subgroup relation ({ital I}4/{ital mmm}{r arrow}{ital t}{sub 2} {r arrow}{ital Immm}), and the transition temperature increases with the ordinal number of the rare earth, indicating the higher the stability of the ScFe{sub 6} Ga{sub 6} -type structure, the smaller the radius of the rare-earth element. Accordingly, the ThMn{sub 12} -type structure is stable for the early rare-earth members and no transition was observed as low as 400 {degree}C. From magnetization curves it is shown that for REFe{sub 12{minus}{ital x}} Ga{sub {ital x}} (RE=rare earth, Y) all magnetic sublattices order simultaneously at temperatures above {Tc} {approximately}400 K. For Y, Lu, and light rare-earth-containing alloys collinear or canted ferromagnetism is observed. The vector of magnetization was found to be close to the {ital a},{ital b} plane. Strong hysteresis effects are revealed in all alloys. Energy products are highest for (Pr,Sm)Fe{sub {approximately}6}Ga{sub {approximately}6}. For the compounds with the heavy rare-earth elements a ferrimagnetic behavior is encountered. Both magnetic sublattices, i.e., Fe and RE, couple antiparallel, exhibiting easy plane anisotropy. The crystallographic transformation, tetragonal-orthorhombic, has little effect on the magnetic behavior of these alloys.
- OSTI ID:
- 6281610
- Journal Information:
- Journal of Applied Physics; (USA), Vol. 68:7; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Magnetism of Pr sub 2 (Fe sub 1 minus x minus y Co sub x Al sub y ) sub 17 alloys with a Th sub 2 Zn sub 17 -type structure
Hole filling and hole creation in the superconducting compounds Bi sub 2 Sr sub 2 minus x R x CuO sub 6+ y ( R =La, Pr, Nd, and Sm)
Related Subjects
GALLIUM ALLOYS
MAGNETIC PROPERTIES
IRON ALLOYS
RARE EARTH ALLOYS
CRYSTAL-PHASE TRANSFORMATIONS
GROUP THEORY
HYSTERESIS
MAGNETIZATION
POWDERS
TERNARY ALLOY SYSTEMS
X-RAY DIFFRACTION
ALLOY SYSTEMS
ALLOYS
COHERENT SCATTERING
DIFFRACTION
MATHEMATICS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SCATTERING
360104* - Metals & Alloys- Physical Properties