Strongly enhanced Curie temperature in carbon-doped Mn5Ge3 films

被引:76
作者
Gajdzik, M [1 ]
Sürgers, C [1 ]
Kelemen, MT [1 ]
Von Löhneysen, H [1 ]
机构
[1] Univ Karlsruhe, Inst Phys, D-76128 Karlsruhe, Germany
关键词
manganese compounds; Curie temperature; magnetic moments; carbon doping;
D O I
10.1016/S0304-8853(00)00494-7
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The structural and magnetic properties of Mn5Ge3Cx films prepared at elevated substrate temperatures T-S are investigated. In particular, films with x greater than or equal to 0.5 and T-S = 680 K exhibit a strongly enhanced Curie temperature T-C = 445 K compared to bulk Mn5Ge3 with T-C = 304 K while at the same time the average Mn moment decreases from 2.6 to 1 mu (B). Structural analysis of these films suggests that the carbon is interstitially incorporated into the voids of Mn octahedra of the hexagonal Mn5Si3-type structure giving rise to a lattice compression. The enhanced ferromagnetic stability in connection with the lattice compression is interpreted in terms of an Mn-Mn interaction mediated by C based on a change in the electronic structure. (C) 2000 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:248 / 254
页数:7
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