著者

Ito Keita Sanai Tatsunori Zhu Siyuan Yasutomi Yoko Toko Kaoru Honda Syuta Ueda Shigenori Takeda Yukiharu Saitoh Yuji Imai Yoji Kimura Akio Suemasu Takashi

出版者

American Institute of Physics

雑誌

Applied physics letters (ISSN:00036951)

巻号頁・発行日

vol.103, no.23, pp.232403, 2013-12

被引用文献数

11 1

---

We evaluated electronic structures and magnetic moments in Co3FeN epitaxial films on SrTiO3(001). The experimentally obtained hard x-ray photoemission spectra of the Co3FeN film have a good agreement with those calculated. Site averaged spin magnetic moments deduced by x-ray magnetic circular dichroism were 1.52 μ B per Co atom and 2.08 μ B per Fe atom at 100 K. They are close to those of Co4N and Fe4N, respectively, implying that the Co and Fe atoms randomly occupy the corner and face-centered sites in the Co3FeN unit cell.

著者

Baba Masakazu Ito Keita Du Weijie Sanai Tatsunori Okamoto Kazuaki Toko Kaoru Ueda Shigenori Imai Yoji Kimura Akio Suemasu Takashi

出版者

American Institute of Physics

雑誌

Journal of applied physics (ISSN:00218979)

巻号頁・発行日

vol.114, no.12, pp.123702, 2013-09

被引用文献数

15

---

The valence band structures of a 35-nm-thick BaSi2 epitaxial film on Si(111) have been explored at room temperature by hard x-ray photoelectron spectroscopy (HAXPES). The experimentally obtained photoelectron spectrum is well reproduced by first-principles calculations based on the pseudopotential method. The top of the valence band consists mainly of Si 3s and 3p states in BaSi2, suggesting that the effective mass of holes is small in BaSi2. This is favorable from the viewpoint of solar cell applications. The observed spectrum shifted slightly to the lower energy side due to n-type conductivity of BaSi2. The valence band top was observed at about 0.8 eV below the Fermi level in the HAXPES spectrum.

著者

Sanai Tatsunori Ito Keita Toko Kaoru Suemasu Takashi

出版者

Elsevier B.V.

雑誌

Journal of crystal growth (ISSN:00220248)

巻号頁・発行日

vol.378, pp.342-346, 2013-09

被引用文献数

5 1

---

We formed CoxFe4−xN (0≤x≤2.9) epitaxial thin films on SrTiO3 (001) substrates by molecular beam epitaxy supplying solid Co and Fe and a radio frequency N2 plasma, simultaneously. The composition ratio of Co/Fe in CoxFe4−xN was controlled by changing the weight ratio of Co to Fe flakes in the crucible of the Knudsen cell used. Epitaxial growth of CoxFe4−xN thin films were confirmed by reflection high-energy electron diffraction and θ–2θ X-ray diffraction patterns. Magnetization versus magnetic field curves measured at room temperature using a vibrating sample magnetometer showed that the axis of easy magnetization was changed from [100] to [110] with increasing x in CoxFe4−xN.

著者

Sanai Tatsunori Ito Keita Toko Kaoru Suemasu Takashi

出版者

Elsevier B.V.

雑誌

Journal of crystal growth (ISSN:00220248)

巻号頁・発行日

vol.357, pp.53-57, 2012-10

被引用文献数

13

---

We attempted to grow CoxFe4−xN epitaxial thin films on SrTiO3(001) substrates by molecular beam epitaxy supplying solid Co and Fe and a radio frequency N2 plasma, simultaneously. The composition ratio of Co/Fe in CoxFe4−xN was controlled by changing the weight ratio of Co to Fe flakes in the crucible of the Knudsen cell used. We confirmed epitaxial growth of CoxFe4−xN (0.4<x<2.9) thin films by reflection high-energy electron diffraction and θ−2θ X-ray diffraction patterns. The in-plane lattice parameter of the CoxFe4−xN films was almost the same as the out-of-plane lattice parameter, and they decreased with increasing Co composition, following Vegard's law.