Atomic bonding state of silicon oxide anodized in extremely diluted hydrofluoric solution

Arai, Taiki*; Yoshigoe, Akitaka; Motohashi, Mitsuya*

Zairyo No Kagaku To Kogaku, 60(5), p.153 - 158, 2023/10

Si oxide films are currently widely used as insulating materials in electronic devices and biomaterials. The atomic bonding state of these films significantly influences the properties of each device, thus it is particularly necessary to understand and control the chemical bonding state between Si and O in the films. In this study, the Si oxide films formed by anodic oxidation on Si substrate surfaces in extremely low concentrations of HF solutions were analyzed by X-ray photoelectron spectroscopy mainly focusing on Si2p and F1s spectra. Although the HF concentration is in the order of ppm, the films contain percent order of F atoms, suggesting the formation of Si-F and Si-O-F bonds in the films. It was also found that the different depth profiles for F and O atoms was observed, indicating that the surface reaction processes seem to be different depending on each element.

First online multireflection time-of-flight mass measurements of isobar chains produced by fusion-evaporation reactions; Toward identification of superheavy elements via mass spectroscopy

Schury, P.*; Wada, Michiharu*; Ito, Yuta*; Kaji, Daiya*; Arai, Fumiya*; MacCormick, M.*; Murray, I.*; Haba, Hiromitsu*; Jeong, S.*; Kimura, Sota*; et al.

Physical Review C, 95(1), p.011305_1 - 011305_6, 2017/01

AA2016-0638.pdf:0.71MB

https://doi.org/10.1103/PhysRevC.95.011305

Using a multireflection time-of-flight mass spectrograph located after a gas cell coupled with the gas-filled recoil ion separator GARIS-II, the masses of several -decaying heavy nuclei were directly and precisely measured. The nuclei were produced via fusion-evaporation reactions and separated from projectilelike and targetlike particles using GARIS-II before being stopped in a helium-filled gas cell. Time-of-flight spectra for three isobar chains, Fr-Rn-At-Po, Fr- Rn-At-Po-Bi, and Fr-Rn-At, were observed. Precision atomic mass values were determined for Fr, Rn, and At. Identifications of Bi, Po, Rn, and At were made with N10 detected ions, representing the next step toward use of mass spectrometry to identify exceedingly low-yield species such as superheavy element ions.

Neutron studies on soft matter by TAIKAN; Tough hydrogels "Double network gels"

Tominaga, Taiki; Suzuki, Junichi*; Takata, Shinichi; Shinohara, Takenao; Oku, Takayuki; Nakatani, Takeshi; Inamura, Yasuhiro; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; et al.

no journal, , 

no abstracts in English

Software development of the smaller-angle neutron scattering instrument TAIKAN of J-PARC

Takata, Shinichi; Suzuki, Junichi*; Shinohara, Takenao; Nakatani, Takeshi; Inamura, Yasuhiro; Ito, Takayoshi*; Oku, Takayuki; Oishi, Kazuki*; Iwase, Hiroki*; Tominaga, Taiki; et al.

no journal, , 

The time-of-flight smaller-angle neutron scattering instrument, named as TAIKAN, has been constructed at the beam line of BL15 in the Materials and Life Science Experimental Facility (MLF) of J-PARC. TAIKAN is designed for efficient measurements in wide-q range of 5 10 to 10[]. The detector system is composed of small-, medium-, and high-angle detector banks and a backward detector bank with arrays of one dimensional He position sensitive detectors, besides the high-resolution detector with spatial resolution of about 0.5 mm will be installed near the center of small angle bank. In the data analysis software of TAIKAN, therefore, it is necessary to be able to execute the data reduction and some corrections to the enormous amounts of data including time information. And then, it is required that the all data processed can be comprehensibly displayed in one screen image. We will present about the data analysis software for TAIKAN now being developed.

Time-shearing measurements of soft matter using J-PARC/TAIKAN (BL15)

Tominaga, Taiki; Takata, Shinichi; Suzuki, Junichi*; Shinohara, Takenao; Oku, Takayuki; Nakatani, Takeshi; Inamura, Yasuhiro; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; et al.

no journal, , 

no abstracts in English

SANS study of static structure of Double-Network polymers

Tominaga, Taiki; Takata, Shinichi; Suzuki, Junichi*; Aizawa, Kazuya; Seto, Hideki; Arai, Masatoshi

no journal, , 

no abstracts in English

SANS study on water in Double network polymers

Tominaga, Taiki; Takata, Shinichi; Suzuki, Junichi*; Seto, Hideki; Aizawa, Kazuya; Arai, Masatoshi

no journal, , 

no abstracts in English

Current status of the small and wide angle neutron scattering instrument TAIKAN at J-PARC

Takata, Shinichi; Suzuki, Junichi*; Oishi, Kazuki*; Iwase, Hiroki*; Shinohara, Takenao; Oku, Takayuki; Nakatani, Takeshi; Inamura, Yasuhiro; Ito, Takayoshi*; Tominaga, Taiki*; et al.

no journal, , 

The small and wide angle neutron scattering instrument, , was installed at the 15 in the Materials and Life Science Experimental Facility, , of . is designed for efficient measurement in wide-q range by using of the wide wavelength and the four detector banks which cover small-, middle-, high-, and backward-angle. At the present stage, 1,216 s are mounted on , where the number is about 50% of the installable total s number. On beam commissioning started in January 2012, and user program began in March 2012. The software of data reduction has newly developed and some sample environment devices such as a sample changer, tension tester, and refrigerator have been improved. In this presentation, we present the current status of about the new software, sample environment devices, and the results on some samples to show the instrument performance of .

Study on the optimization of the solidification of low-level radioactive liquid waste by magnesium phosphate cement

Yamanaka, Taiki*; Arai, Tsuyoshi*; Sato, Fuminori; Ito, Yoshiyuki; Horiguchi, Kenichi

no journal, , 

no abstracts in English

Effect of substrate surface conditions before anodization on shape of Si micro-nano rolls

Qiao, Y.*; Arai, Taiki*; Suzuki, Toshiaki*; Yoshigoe, Akitaka; Niwa, Masaaki*; Motohashi, Mitsuya*

no journal, , 

Roll-like structures with a thickness of about 1 m fabricated by anodization of the surface of single-crystalline Si wafers have the potential to be applied to a variety of devices. With the aim of controlling the thickness and length of the rolls, the influence of the surface condition of the Si substrate before anodization was investigated. It was found that Pt coating before anodization was effective in controlling the thickness of rolls. Furthermore, it was found that this result was not affected by the doping types.

Oxidation mechanism of Si surface anodized with extremely diluted HF solution

Arai, Taiki*; Qiao, Y.*; Suzuki, Toshiaki*; Yoshigoe, Akitaka; Motohashi, Mitsuya*

no journal, , 

Si oxide films are currently widely used as insulating materials in electronic devices and biomaterials. The chemical bonding of these films significantly influences the properties of each device, thus it is particularly necessary to understand and control the chemical bonds between Si and O in the films in detail. In this study, the Si oxide films formed by anodic oxidation on Si surfaces in extremely low concentrations of HF solutions were analyzed by X-ray photoelectron spectroscopy on Si2p and F1s spectra. Although the HF concentration is in the order of ppm, the films contain percent order of F atoms, suggesting the formation of Si-F and Si-O-F bonds in the films. It was also found that the different depth profiles for F and O atoms was observed, indicating that the surface reaction processes seem to be different depending on each element.