Real-time observation of rotational twin formation during molecular-beam epitaxial growth of GaAs on Si (111) by X-ray diffraction

Suzuki, Hidetoshi*; Nakata, Yuka*; Takahashi, Masamitsu; Ikeda, Kazuma*; Oshita, Yoshio*; Morohara, Osamu*; Geka, Hirotaka*; Moriyasu, Yoshitaka*

AIP Advances (Internet), 6(3), p.035303_1 - 035303_6, 2016/03

https://doi.org/10.1063/1.4943511

Direct observation of strain in InAs quantum dots and cap layer during molecular beam epitaxial growth using X-ray diffraction

Shimomura, Kenichi*; Suzuki, Hidetoshi*; Sasaki, Takuo; Takahashi, Masamitsu; Oshita, Yoshio*; Kamiya, Itaru*

Journal of Applied Physics, 118(18), p.185303_1 - 185303_7, 2015/11

https://doi.org/10.1063/1.4935456

Strain analysis of III-V epitaxial growth by synchrotron X-ray diffraction

Sasaki, Takuo; Takahashi, Masamitsu

Nihon Kessho Seicho Gakkai-Shi, 42(3), p.210 - 217, 2015/10

AA2015-0738.pdf:2.23MB

https://doi.org/10.19009/jjacg.42.3_210

three-dimensional X-ray reciprocal-space mapping of InGaAs multilayer structures grown on GaAs(001) by MBE

Sasaki, Takuo; Takahashi, Masamitsu; Suzuki, Hidetoshi*; Oshita, Yoshio*; Yamaguchi, Masafumi*

Journal of Crystal Growth, 425, p.13 - 15, 2015/09

https://doi.org/10.1016/j.jcrysgro.2015.03.044

Role of liquid indium in the structural purity of wurtzite InAs nanowires that grow on Si(111)

Biermanns, A.*; Dimakis, E.*; Davydok, A.*; Sasaki, Takuo; Geelhaar, L.*; Takahashi, Masamitsu; Pietsch, U.*

Nano Letters, 14(12), p.6878 - 6883, 2014/12

https://doi.org/10.1021/nl502878a

Monitoring of airborne C discharge at RI facilities; A Comparison of collection and oxidation methods

Ueno, Yumi; Koarashi, Jun; Iwai, Yasunori; Sato, Junya; Takahashi, Teruhiko; Sawahata, Katsunori; Sekita, Tsutomu; Kobayashi, Makoto; Tsunoda, Masahiko; Kikuchi, Masamitsu

Hoken Butsuri, 49(1), p.39 - 44, 2014/03

http://doi.org/10.5453/jhps.49.39

http://doi.org/10.5453/jhps.49.2

The Japan Atomic Energy Agency has conducted a monthly monitoring of airborne C discharge at the forth research building (RI facility) of the Tokai Research and Development Center. In the current monitoring, C, which exists in various chemical forms in airborne effluent, is converted into CO with CuO catalyst and then collected using monoethanolamine (MEA) as CO absorbent. However, this collection method has some issues on safety management because the CuO catalyst requires a high heating temperature (600C) to ensure a high oxidation efficiency and the MEA is specified as a poisonous and deleterious substance. To establish a safer, manageable and reliable method for monitoring airborne C discharge, we examined collection methods that use different CO absorbents (MEA and Carbo-Sorb E) and oxidation catalysts (CuO, Pt/Alumina and Pd/ZrO). The results showed 100% CO collection efficiency of MEA during a 30-day sampling period under the condition tested. In contrast, Carbo-Sorb E was found to be unsuitable for the monthly-long CO collection because of its high volatile nature. Among the oxidation catalysts, the Pd/ZrO showed the highest oxidation efficiency for CH at a lower temperature.

Real-time observation of crystallographic tilting InGaAs layers on GaAs offcut substrates

Nishi, Toshiaki*; Sasaki, Takuo; Ikeda, Kazuma*; Suzuki, Hidetoshi*; Takahashi, Masamitsu; Shimomura, Kenichi*; Kojima, Nobuaki*; Oshita, Yoshio*; Yamaguchi, Masafumi*

AIP Conference Proceedings 1556, p.14 - 17, 2013/09

https://doi.org/10.1063/1.4822188

Quantitative monitoring of InAs quantum dot growth using X-ray diffraction

Takahashi, Masamitsu

Journal of Crystal Growth, 401, p.372 - 375, 2013/09

https://doi.org/10.1016/j.jcrysgro.2013.11.012

X-ray diffraction study of crystal growth dynamics during molecular-beam epitaxy of III-V semiconductors

Takahashi, Masamitsu

Journal of the Physical Society of Japan, 82(2), p.021011_1 - 021011_14, 2013/02

https://doi.org/10.7566/JPSJ.82.021011

GaAs surface under molecular-beam epitaxial growth conditions

Takahashi, Masamitsu

Hyomen Kagaku, 33(9), p.507 - 512, 2012/09

https://doi.org/10.1380/jsssj.33.507

Surface structures of GaAs(001) under growth conditions have been investigated using in situ X-ray diffraction. The atomic arrangements of GaAs(001) surface stabilized at an elevated temperature under as pressure were quantitatively determined in a molecular-beam epitaxy chamber integrated with an X-ray diffractometer. With the help of high angular resolution of synchrotron radiation, disordered structures appearing in the transition from (24) to other phases were clarified. Energy tunability of synchrotron X-rays allowed for element-specific analysis of the c(44) structure, providing direct evidence for Ga-As heterodimer formation.