Influence of structural parameters on magnetoresistive properties of CuFeNi melt spun ribbons

详细信息    查看全文

• 作者：S. Cazottes ; F. Danoix ; A. Fnidiki ; D. Lemarch ; M. Baricco
• 关键词：Atom probe tomography ; Granular system ; Giant magnetoresistance
• 刊名：Ultramicroscopy
• 出版年：2009
• 出版时间：April 2009
• 年：2009
• 卷：109
• 期：5
• 页码：625-630
• 全文大小：1234 K

文摘

The microstructure of Cu₈₀Fe₁₀Ni₁₀ (at % ) granular ribbon was investigated by means of atom probe tomography (APT). A granular system is composed of magnetic precipitates embedded in a non-magnetic matrix. In this ribbon, the magnetic precipitates have a diameter smaller than 5 nm in the as-spun state, and their crystallographic structure is very similar to the one of the matrix, which makes it difficult to characterize them using conventional techniques. Those data are of great importance to understand the magnetic and the transport behaviour of these ribbons. Using atom probe tomography, a 3D reconstruction of the microstructure of the as-spun and annealed ribbons was achieved and a precise characterization of the compositions of the two phases and of the composition profile at interfaces was carried out. In the as-spun state the composition of the matrix is Cu₈₉Fe₃Ni₈, the one of the precipitates is Cu₃₀Fe₄₀Ni₃₀. Upon annealing, the precipitates get enriched in iron. After annealing at 600 °C for 24 h, the measured compositions are close to the one predicted by Thermocalc, with Cu₉₄Fe₁Ni₅ for the matrix and Cu₅Fe₆₄Ni₃₁ for the precipitates.