Structure and Magnetism of Mn5Ge3 Nanoparticles
AbstractIn this work, we investigated the magnetic and structural properties of isolated Mn5Ge3 nanoparticles prepared by the cluster-beam deposition technique. Particles with sizes between 7.2 and 12.6 nm were produced by varying the argon pressure and power in the cluster gun. X-ray diffraction (XRD)and selected area diffraction (SAD) measurements show that the nanoparticles crystallize in the hexagonal Mn5Si3-type crystal structure, which is also the structure of bulk Mn5Ge3. The temperature dependence of the magnetization shows that the as-made particles are ferromagnetic at room temperature and have slightly different Curie temperatures. Hysteresis-loop measurements show that the saturation magnetization of the nanoparticles increases significantly with particle size, varying from 31 kA/m to 172 kA/m when the particle size increases from 7.2 to 12.6 nm. The magnetocrystalline anisotropy constant K at 50 K, determined by fitting the high-field magnetization data to the law of approach to saturation, also increases with particle size, from 0.4 × 105 J/m3 to 2.9 × 105 J/m3 for the respective sizes. This trend is mirrored by the coercivity at 50 K, which increases from 0.04 T to 0.13 T. A possible explanation for the magnetization trend is a radial Ge concentration gradient. View Full-Text
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Tosun, O.; Salehi-Fashami, M.; Balasubramanian, B.; Skomski, R.; Sellmyer, D.J.; Hadjipanayis, G.C. Structure and Magnetism of Mn5Ge3 Nanoparticles. Nanomaterials 2018, 8, 241.
Tosun O, Salehi-Fashami M, Balasubramanian B, Skomski R, Sellmyer DJ, Hadjipanayis GC. Structure and Magnetism of Mn5Ge3 Nanoparticles. Nanomaterials. 2018; 8(4):241.Chicago/Turabian Style
Tosun, Onur; Salehi-Fashami, Mohammed; Balasubramanian, Balamurugan; Skomski, Ralph; Sellmyer, David J.; Hadjipanayis, George C. 2018. "Structure and Magnetism of Mn5Ge3 Nanoparticles." Nanomaterials 8, no. 4: 241.
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