Abstract

The structural evolution and magnetic property of Mn-rich clusters in GeMn thin films grown at 70°C by molecular beam epitaxy has been systematically investigated by TEM, EDS and SQUID. It was discovered that, by controlling the Mn concentration, the morphology of coherent Mn-rich clusters can be manipulated from tadpole to nanocolumn shapes. For a particular Mn concentration, the critical thickness to form coherent Mn-rich clusters at 70°C has been identified. Magnetic measurements show a complex magnetic behavior, which is mainly related to the Mn-rich clusters or precipitates. Our results also reveal that a flat surface of the Ge buffer layer plays an important role in producing vertically aligned tadpoles and nanocolumns.

Date

October 22, 2010

Authors

Yong Wang, Faxian Xiu, Ya Wang, Xufeng Kou, Ajey P Jacob, Kang L Wang, Jin Zou

Journal

Journal of alloys and compounds

Volume

508

Issue

2

Pages

273-277

Publisher

Elsevier