Magnetic properties of cobalt and cobalt-platinum alloy nanoparticles synthesized via microemulsion technique

被引：45

作者：

Kumbhar, A ^{[1
]}

Spinu, L ^{[1
]}

Agnoli, F ^{[1
]}

Wang, KY ^{[1
]}

Zhou, WL ^{[1
]}

O'Connor, CJ ^{[1
]}

机构：

[1] AMRI UNO, New Orleans, LA 70148 USA

来源：

IEEE TRANSACTIONS ON MAGNETICS | 2001年 / 37卷 / 04期

关键词：

core-shell; nanoparticles; reverse micelle; superparamagnetism;

D O I：

10.1109/20.951128

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

Metallic cobalt and cobalt-platinum alloys of various nanometer sizes have been synthesized via the microemulsion technique and their magnetic properties have been characterized. Preparation of cobalt and cobalt-platinum alloy nanoparticles was achieved by reducing aqueous metallic salts confined in the polar regions of the reverse micelle of cetyltrimethyl bromide (CTAB) with sodium borohydride. These particles are further coated with gold by reducing aqueous gold salts with borohydride. The dc susceptibility data of 15 mn gold coated Co, CoPt and COPt3 particles exhibit a blocking temperature of 4 K, 80 K and 106 K and coercivity of 20 Oe, 200 Oe, and 415 Oe at 10 K, respectively. Annealing these samples at 400 degreesC further enhanced their magnetic properties. The two cobalt-platinum alloys have been synthesized and characterized by x-ray powder diffraction and transmission electron microscopy.

引用

页码：2216 / 2218

页数：3

共 10 条

[1] Magnetism of nanophase metal and metal alloy particles formed in ordered phases [J].