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.

Study on cathodic reaction control efficiency by low alloy steels

Akashi, Masatsune*; Fukaya, Yuichi*; Asano, Hidekazu*

JNC TJ8400 2000-015, 46 Pages, 2000/02

JNC-TJ8400-2000-015.pdf:2.96MB

Difference of hydrogen generation phenomena on the surface of the Steels were not observed between carbon steel, atmospheric corrosion resisting steel and 5%-Ni steel. Rust layer was formed on these three-type of steels by steam oxidation method. And the chemical composition of the rust for the steels were basically two (2) layers structure for the previous two steels as hematite (FeO) based for the outer layer and magnetite (FeO) based for the inner layer. And for the last steel, it had three (3) layer in the rust as hematite (FeO) based for the outer layer, magnetite (FeO) based for the intermediate layer and Ni based layer for the inner layer. These steels showed mostly same Tafel gradient in their cathodic polarization curves compare with that for no rust specimens. However, the exchange current density which reaction is assumed as a hydrogen generation reaction was largely increased. The cathodic reaction for each steels whose surface is covered by magnetite layer might be accelerated, then the corrosion rate was considered as accelerated, too.

Test of the palladium diffuser in the JAERI fuel cleanup system in the Tritium Systems Test Assembly

Konishi, Satoshi; Ohira, Shigeru; Hayashi, Takumi; Watanabe, Tetsuo*; Inoue, Masahiko*; Naruse, Yuji; Okuno, Kenji; Barnes, J. W.*; W.Harbin*; Bartlit, J. R.*; et al.

JAERI-M 93-088, 18 Pages, 1993/03

JAERI-M-93-088.pdf:0.47MB

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.