Spatial chemical inhomogeneity and local electronic structure of Mn-doped Ge ferromagnetic semiconductors.
We have investigated the chemical distributions and the local electronic structure of potential diluted magnetic semiconductor Ge0.94Mn0.06 single crystals using scanning photoelectron microscopy (SPEM), x-ray absorption spectroscopy (XAS), and photoemission spectroscopy (PES). The SPEM image shows the stripe-shaped microstructures, which arise from the chemical phase separation between the Mn-rich and Mn-depleted phases. The Mn 2p XAS shows that the Mn ions in the Mn-rich region are in the divalent high-spin Mn2+ states but that they do not form metallic Mn clusters. The Mn 3d PES spectrum exhibits a peak centered at approximately 4 eV below E(F) and the negligible spectral weight near E(F). This study suggests that the observed ferromagnetism in Ge1-xMnx arises from the phase-separated Mn-rich phase.
Kang
J-S
JS
Department of Physics, The Catholic University of Korea, Puchon 420-743, Korea.
Kim
G
G
Wi
S C
SC
Lee
S S
SS
Choi
S
S
Cho
Sunglae
S
Han
S W
SW
Kim
K H
KH
Song
H J
HJ
Shin
H J
HJ
Sekiyama
A
A
Kasai
S
S
Suga
S
S
Min
B I
BI