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ID 18667
file
creator
Fukuda, H.
Fujii, Hironobu
Kamura, H.
Hasegawa, Yuichi
Kikugawa, Naoki
Fujita, Toshizo
abstract
We studied the dilute substitution effect on magnetic and transport properties in an unstable ferromagnet CeFe2 with a C15 cubic Laves-phase structure. In the Co substitution system Ce(Fe1-xCox)2 with x≤0.10, while the Curie temperature T c decreases with increasing the Co concentration, an antiferromagnetic ordering appears in the low temperature region for x≥0.05, and the transition temperature T o from ferromagnetic to antiferromagnetic states monotonously increases with increasing the Co concentration. On the other hand, in the Sc substitution system (Ce1-ySCy)Fe2 with y≤0.10, both the Curie temperature T c and saturation magnetization M s at 4.2 K gradually increase with increasing the Sc concentration. Despite the decrease in lattice parameter upon substitution in both the systems, an antiferromagnetic ground state is stabilized in Ce(Fe1-xCox)2, whereas a ferromagnetic ground state is stabilized in (Ce1-yScy)Fe2. These results indicate that the Fe 3d–Fe 3d ferromagnetic exchange interaction and the antiferromagnetic spin correlation arising from the Ce4f–Fe3d hybridization compete in CeFe2, and the enhancement/depression of the 4f-3d hybridization effect might make the ferromagnetic ground state in CeFe2 unstable/stable. Furthermore, Ce(Fe1-xCox)2 exhibited a negative giant magnetoresistance reaching about δρ/ρ= ∼60–65 % at 4.2 K, which is accompanied by a metamagnetic transition from antiferromagnetic to ferromagnetic states. The giant magnetoresistance effect is originated from the reconstruction of Fermi surface due to the collapse of the superzone gap after the metamagnetic transition.
journal title
Physical Review B - Condensed Matter and Materials Physics
volume
Volume 63
issue
Issue 5
start page
054405-1
end page
054405-9
date of issued
2001-01-03
publisher
American Physical Society
issn
0163-1829
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
rights
Copyright (c) 2001 American Physical Society.
relation url
department
Graduate School of Advanced Sciences of Matter