Structural and magnetic properties of Mn5Ge3 nanoclusters dispersed in MnxGe1−x/Ge(0 0 1)2 × 1 diluted magnetic semiconductors
- 作者：P. De Padova ; L. Favre ; I. Berbezier ; B. Olivieri ; A. Generosi ; B. Paci ; V. Rossi Albertini ; P. Perfetti ; C. Quaresima ; J.-M. Mariot ; A. Taleb-Ibrahimi ; M.C. Richter ; O. Heckmann ; F. D’ ; Orazio
- 关键词：MnGe diluted magnetic semiconductor ; Mn5Ge3 nanoclusters ; HRTEM ; EDXR ; MOKE
- 刊名：Surface Science
- 出版年：2007
- 期刊代码：104_00396028
- 类别：ch
- 出版时间：15 September 2007
- 卷：601
- 期：18
- 页码：4370-4374
- 文件大小：629 K
摘要
We investigated the structural and magnetic properties of MnxGe1−x, with 0.02 mg src="http://www.sciencedirect.com/scidirimg/entities/2a7d.gif" alt="less-than-or-equals, slant" border=0> x mg src="http://www.sciencedirect.com/scidirimg/entities/2a7d.gif" alt="less-than-or-equals, slant" border=0> 0.1. The MnxGe1−x samples were grown on Ge(0 0 1)2 × 1 by molecular beam epitaxy, at a substrate temperature of 520 K. The samples were characterized in situ by reflection high-energy electron diffraction and ex situ by high-resolution transmission electron microscopy, energy dispersive X-ray reflectivity and magneto-optical Kerr effect. From microscopy images we evidenced on all samples the presence of Mn5Ge3 nanocrystallites in addition to the MnxGe1−x diluted magnetic semiconductor with an estimated Mn concentration x ≈ 1.5%. The size and the density of the Mn5Ge3 precipitates were found to increase with increasing the Mn concentration x. Magnetic analysis showed ferromagnetism with a Curie temperature of 280 K for all samples.