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

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