Reduction of Sintering during Annealing of FePt Nanoparticles Coated with Iron Oxide
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- 作者：Chao Liu ; Xiaowei Wu ; Timothy Klemmer ; Nisha Shukla ; Dieter Weller ; Anup G. Roy ; Mihaela Tanase ; and David Laughlin
- 刊名：Chemistry of Materials
- 出版年：2005
- 出版时间：February 8, 2005
- 年：2005
- 卷：17
- 期：3
- 页码：620 - 625
- 全文大小：967K
- 年卷期：v.17,no.3(February 8, 2005)
- ISSN：1520-5002
文摘
FePt/iron oxide core/shell nanoparticles are synthesized by a two step polyol process with 1,2-hexadecanediol as the reducing reagent. Monodispersed 2.6-nm FePt nanoparticles are first obtained byreduction of iron(III) acetylacetonate and platinum(II) acetylacetonate. These preformed FePt nanoparticlesare then used as seeds and an iron oxide shell is formed in the second synthesis step. The role of the ironoxide shell on sintering of FePt nanoparticles is investigated. Annealing studies show that these FePt/iron oxide core/shell structures are stable after annealing at 550 
C for 30 min at which 2.6-nm FePtnanoparticles without oxide shell coating start to sinter. Low-temperature magnetic hysteresis behaviorof the annealed core/shell nanoparticles suggests exchange coupling between the magnetically hard FePtcore and the magnetically soft iron oxide shell.
C for 30 min at which 2.6-nm FePtnanoparticles without oxide shell coating start to sinter. Low-temperature magnetic hysteresis behaviorof the annealed core/shell nanoparticles suggests exchange coupling between the magnetically hard FePtcore and the magnetically soft iron oxide shell.