AVS 51st International Symposium
    Semiconductors Monday Sessions
       Session SC+MI-MoM

Paper SC+MI-MoM3
Structural and Magnetic Properties of a Magnetic Semiconductor MnGeN@sub2@ Grown by MBE

Monday, November 15, 2004, 9:00 am, Room 304B

Session: Dilute Magnetic and Ferromagnetic Semiconductors
Presenter: L. Li, University of Wisconsin, Milwaukee
Authors: S.H. Cheung, University of Wisconsin, Milwaukee
M.L. Harland, University of Wisconsin, Milwaukee
V.K. Lazarov, University of Wisconsin, Milwaukee
Y. Zhang, Peking University, China
M. Weinert, University of Wisconsin, Milwaukee
M. Gajdardziska-Josifovska, University of Wisconsin, Milwaukee
Z. Gai, Peking University, China
L. Li, University of Wisconsin, Milwaukee
Correspondent: Click to Email
A novel magnetic semiconductor MnGeN@sub2@ was synthesized on 6H-SiC(0001), Al@sub2@O@sub3@(0001), and MgO(111) substrates by plasma assisted molecular beam epitaxy. In situ reflection high-energy diffraction, ex situ atomic force microscopy and transmission electron microscopy (TEM) investigations indicate that the films grown are epitaxial on all three substrates, with the ones on MgO having the best overall quality. Detailed analysis of high-resolution TEM digital diffractograms and convergent beam electron diffraction patterns of the films show that the MnGeN@sub2@ is orthorhombic, and has the following crystallographic orientation relationships with the substrate: MnGeN@sub2@(001)//MgO(111), MnGeN@sub2@(100)//MgO(11-1), and MnGeN@sub2@(210)//MgO(01-1). Investigations by SQUID magnetometry indicate that the magnetic properties of the films can be controlled by the stoichiometry, i.e. Mn/Ge ratio, varying from paramagnetic to ferromagnetic, with the ferromagnetic samples exhibiting a Curie temperature above 300 K.