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Hasegawa, Yuri; Yamada, Yoichi*; Sasaki, Masahiro*
Vacuum and Surface Science, 61(6), p.366 - 371, 2018/06
Molecular arrangements and electronic states of well-ordered (DNTT) and picene thin film on single crystal were measured by means of scanning tunneling microscope (STM) and angle-resolved photoemission spectroscopy, respectively. DNTT and picene form single crystalline-like molecular arrangement on inert Au(111) substrate. Splitting of HOMO energy due to overlapping with adjacent molecules was suggested by ultraviolet photoemission spectroscopy (UPS) and density functional theory (DFT) calculation. On the other hand, one-dimensional ordering of those molecule was observed on anisotropic Ag(110) substrate. However, the HOMO band dispersion was found to be 200 meV at maximum, showing that the overlapping of HOMO was smaller in such arrangement comparing with that in their single crystal.
Kwon, E.*; Komatsu, Kenichiro*; Yamada, Yoichi*; Hasegawa, Yuri*; Sato, Sho*; Sakai, Seiji; Kawachi, Kazuhiko*; Yokoo, Kuniyoshi*; Ono, Shoichi*; Kasama, Yasuhiko*; et al.
no journal, ,
Hasegawa, Yuri; Honda, Mitsunori; Suzuki, Shinichi; Yaita, Tsuyoshi
no journal, ,
For environmental restoration, recycling of radioactive polluted soil has been one the latest issues. Recently, elimination of radioactive elements accompanied by growth of various crystal structures from a typical mineral in the Fukushima area was reported to be realized only by heating it with alkali salt. Since crystals with useful electronic property is possibly obtained with this processing, improvement of the processing is required to make the crystals available as more feasible materials. However, crystal growth from minerals has hardly been studied since low crystalinity of the natural soil has hindered structural analysis. Therefore, in this study, the initial stage of the crystal growth using minerals with high crystalinity was investigated.
Honda, Mitsunori; Goto, Takuya*; Sakanaka, Yoshihide*; Hasegawa, Yuri; Suzuki, Shinichi; Yaita, Tsuyoshi
no journal, ,
no abstracts in English
Hasegawa, Yuri; Honda, Mitsunori; Suzuki, Shinichi; Yaita, Tsuyoshi
no journal, ,
Recycling of radioactive polluted soil has been one the latest issues in environmental restoration. Among minerals in soil, weathered biotite fix Cs strongly. Recently, elimination of Cs accompanied by growth of various kind of crystal from weathered biotite was realized only by heating with alkali salt (NaCl-CaCl). Since some of those crystals are available as a functional material, further understanding of the process of crystal growth is required for selective growth. However, understating the crystal growth is difficult because WB consists of weathered and un-weathered phase. Therefore, in this study, crystal growth form un-weathered biotite was investigated. XRD measurement revealed growth of FeO
, Wadalite, and pyroxene were observed from 2 
m of biotite, whereas pyroxene was not observed from 75m of biotite. In addition, pyroxene was not observed even with 2m of biotite when NaCl:CaCl=7:3. These result suggest size of biotite and NaCl:CaCl ratio affect selective growth.
Hasegawa, Yuri; Honda, Mitsunori; Suzuki, Shinichi; Yaita, Tsuyoshi
no journal, ,
We investigated the factor of crystal growth from biotite in order to fabricate functional material from the radioactive polluted soil. Among minerals in the soil, weathered biotite is known to fix Cs strongly. Recently, elimination of Cs accompanied by growth of pyroxene, wadalite, FeO,CaCO from weathered biotite was realized by heating with alkali salt (NaCl-CaCl). In this study, selective growth of wadalite from biotite and suppression of pyroxene were observed when alkali salt with ratio of NaCl:CaCl=3:7 was utilized. This observation indicates that NaCl:CaCl ratio possibly affects selective growth of silicate mineral from biotite.
Hasegawa, Yuri; Honda, Mitsunori; Suzuki, Shinichi; Yaita, Tsuyoshi
no journal, ,
Biotite has been getting great attention in the field of reducing the volume of radioactive contaminated soil since biotite has been suggested to fix Cs strongly by theory and experiment. Recently, elimination of Cs accompanied by crystal growth of pyroxene, wadalite, FeO and CaCO by heating with mixed alkali-salt (NaCl-CaCl) was observed. In order to make them available as functional material, selective growth is required. In this study, selective growth of wadalite from biotite and suppression of pyroxene were observed when alkali salt with ratio of NaCl:CaCl=3:7 was utilized. This observation indicates that NaCl:CaCl ratio possibly affects selective growth of silicate mineral from biotite.
