L10 phase transformation and magnetic behaviors of (Fe, FePt, FePtCu)-C nanocomposite films -: art. no. 124303

被引：13

作者：

Mi, WB ^{[1
]}

Liu, H ^{[1
]}

Li, ZQ ^{[1
]}

Wu, P ^{[1
]}

Jiang, EY ^{[1
]}

Bai, HL ^{[1
]}

机构：

[1] Tianjin Univ, Tainjin Key Lab Low Dimens Mat Phys & Preparing T, Inst Adv Mat Phys, Fac Sci, Tianjin 300072, Peoples R China

来源：

JOURNAL OF APPLIED PHYSICS | 2005年 / 97卷 / 12期

基金：

中国国家自然科学基金;

关键词：

D O I：

10.1063/1.1929089

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

As-deposited (Fe, FePt, FePtCu)-C nanocomposite films with fixed C atomic fraction x(c)=47 fabricated using facing-target sputtering method at room temperature are composed of similar to 2-3-nm amorphous metal granules buried in a-C matrix. Annealing at high temperatures turns the amorphous granules into alpha-Fe, alpha-Fe- and L1(0)-structured FePt, and L1(0)-ordered FePtCu for Fe-C, FePt-C, and FePtCu-C films, respectively, and makes a-C preferential graphitization. As-deposited granules are superparamagnetic at 300 K, and ferromagnetic at 5 K. The zero-field-cooled (ZFC) and field-cooled (FC) curves reveal that there exist strong intergranular interactions at temperatures below 300 K, and the size distribution of granules becomes broad by Pt and Cu addition. The M-H loop of annealed Fe31Pt22C47 films exhibits a two-step saturation behavior because of the coexistence of soft and hard ferromagnetic phases. As the Cu atomic fraction is 14%, the coercivity of annealed Fe23Pt16Cu14C47 films reaches a large value of similar to 11.2 kOe at 5 K and decreases to similar to 7.2 kOe at 300 K. (c) 2005 American Institute of Physics.

引用

页数：6

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