H. Sato

Carrier-induced ferromagnetism in Ge0.92Mn0.08Te epilayers with a Curie temperature up to 190 K

IV-VI diluted magnetic semiconductor Ge0.92Mn0.08Te epilayers are grown on BaF2 substrates by molecular beam epitaxy. The ferromagnetic behaviors, such as the spontaneous magnetization, the coercive field, and the Curie temperature TC, are altered by the hole concentration p. In the Ge0.92Mn0.08Te layer with high p, strong magnetic anisotropy and the temperature dependence of the magnetization expected for homogeneous ferromagnets are observed, implying that long-range ordering is induced by the holes. The maximum TC reaches 190 K for 1.57×1021 cm−3.

IV-VI diluted magnetic semiconductor Ge1-xmnxTe epilayer grown by molecular beam epitaxy

Growth of the IV-VI diluted magnetic semiconductor Ge1−xMnxTe by molecular beam epitaxy is reported. The epitaxial growth of Ge1−xMnxTe (x=0.13) on BaF2 (111) with a GeTe buffer layer is confirmed by x-ray diffraction and reflection high-energy electron diffraction. The ferromagnetic order is clearly established by the magnetization and magnetotransport measurements. The Curie temperature of 100K is obtained for the hole concentration of 7.86×1020cm−3. The existence of the strong p-d exchange which gives rise to the ferromagnetic order is revealed by the hard x-ray photoemission measurements.

X‐ray Magnetic Circular Dichroism of Ferromagnetic Semiconductor Ge1−xMnxTe

We have investigated 3d electronic and magnetic states of the Mn ion in IV–VI diluted magnetic semiconductor Ge1−xMnxTe using soft x‐ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD). The rich structure in XAS and XMCD spectra suggests that Mn has highly localized state. The XMCD intensity is good agreement with the spontaneous magnetization of the sample. The contribution of the spin and orbital angular momenta to the magnetic moment is examined using the sum rules.