Title
Synthesis and magnetic properties of core-shell structured (NiCo)O(AFM)-NiCo(FM) magnetic nanoparticles
Date Issued
01 January 2002
Access level
metadata only access
Resource Type
journal article
Author(s)
Jeyadevan B.
Chinnasamy C.N.
Iwasaki Y.
Hobo A.
Shinoda K.
Tohji K.
Kasuya A.
Publisher(s)
Institute of Electrical and Electronics Engineers Inc.
Abstract
We have succeeded in the synthesis of nanometer size monodispersed Ni-Co metal particles through the modified-polyol process. Ni-Co metal particles of about 40 and 100 nm with Co-rich core and Ni-rich shell were produced by the manipulation of the reaction kinetics through a suitable selection of hydroxyl ion concentration in the ethylene glycol-Ni-Co system. Furthermore, core-shell structured (NiCo)O(AFM)-NiCo(FM) was produced by oxidizing particles at 533 K in air for different times. The magnetic properties, especially the exchange-bias (HE) fields of 40 and 100-nm core-shell structured particles synthesized under similar conditions behaved differently. However, their behavior was explained considering exchange biased interactions at (NiCo)O(AFM)-NiCo(FM), and (Co)O(AFM)-Co(FM) interfaces with two different exchange coupling constants. The 40 nm particles oxidized for 4h and composed of (NiCo)O(AFM)-NiCo(FM), exhibited a maximum HE field of 36 and 201 Oe at 298 and 77 K, respectively.
Start page
2595
End page
2597
Volume
38
Issue
5 I
Language
English
OCDE Knowledge area
Nano-tecnología
Subjects
Scopus EID
2-s2.0-0036761973
Source
IEEE Transactions on Magnetics
ISSN of the container
00189464
Sponsor(s)
Manuscript received February 13, 2002; revised May 21, 2002. This work was supported in part by a Grant-in-Aid for Priority Research (11165202) from the Ministry of Education, Science, Culture, and Sports of Japan and CREST of Japan Science and Technology Institute. B. Jeyadevan, C. N. Chinnasamy, A. Hobo, K. Shinoda, and K. Tohji are with Tohoku University, Sendai 980-8579, Japan (e-mail: jeya@ni4.earth.to-hoku.ac.jp). O. Perales-Perez is with the School of Metallurgy, Universidad Nacional de Ingenieria, Lima 25, Peru. Y. Iwasaki is with Sony Corporation Core Technology and Network Company, Sendai Technology Center, Tagajo-shi, Miyagi ken 985-0842, Japan. A. Kasuya is with Center for Interdisciplinary Research, Tohoku University, Sendai 980-8578, Japan. Digital Object Identifier 10.1109/TMAG.2002.803219.
Sources of information:
Directorio de Producción Científica
Scopus