TY - JOUR
T1 - Hydrogenation characteristics and magnetic properties of fine Ni particles coated with Pd
AU - Otani, Yoshichika
AU - Miyajima, Hideki
AU - Yamaguchi, Makoto
AU - Nozaki, Yukio
AU - Manago, Takashi
AU - Fagan, A. J.
AU - Coey, J. M.D.
N1 - Funding Information:
the interface anisotropy impeding saturation. This is clearly seen in Fig. 2. Before hydrogenation, the value of aNi above 10 K lies at about 56.5 emu/g which is somewhat lower than that of pure Ni (58.87 emu/g at T= 4.2 K). The magnetization gNi however increases to 58.5 emu/g at 4.2 K. The same behavior was observed in the thermomagnetic curve measured in an applied field of 5 T. The steep rise of the magnetization appeared below about 20 K This suggests that there is induced magnetizaiion in the Pd shell. The difference in the saturation magnetization crNi between 4.2 and 20 K gives the magnetic moment 0.2~~ per Pd atom. After hydrogenation, the saturation magnetization UNi hardly depends on temperature and takes the value around 55 emu/g. As is clearly seen in the inset of Fig. 2, the difference between before and after hydrogenation can not be explained by just considering the suppression of paramagnetic contribution of Pd (15 0.05 emu/g), There may be a possibility that the absorbed hydrogen at the interface or in the Ni core depresses ferromagnetism of the surface layer of the Ni core. The thickness of the nonmagnetic surfaface layer is about 2 nm. Acknowledgement: The authors would like express their thanks to Mr. H. Sakamoto in Tanaka Kikinnzoku Inc. for his kind offer of the information of the Ni/Pd particles. They also thank to Mr. H. Masuda in TOE1 Kogyo Co. Ltd. for his providing the high sensitive alternating gradient force magnetometer. This work was supported in part by the Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture in Japan.
PY - 1995/2
Y1 - 1995/2
N2 - Hydrogenation characteristics and magnetic properties of Ni fine particles with thin Pd shell were investigated. The Pd shell appeared to turn weakly ferromagnetic below about 20 K, but this magnetic polarization was suppressed by hydrogenation.
AB - Hydrogenation characteristics and magnetic properties of Ni fine particles with thin Pd shell were investigated. The Pd shell appeared to turn weakly ferromagnetic below about 20 K, but this magnetic polarization was suppressed by hydrogenation.
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U2 - 10.1016/0304-8853(94)00797-7
DO - 10.1016/0304-8853(94)00797-7
M3 - Article
AN - SCOPUS:17044443226
VL - 140-144
SP - 403
EP - 404
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
SN - 0304-8853
IS - PART 1
ER -