Evidence for pore surface dependent positronium thermalization in mesoporous silica/hybrid silica films

Chunqing He; Toshiyuki Ohdaira; Nagayasu Oshima; Makoto Muramatsu; Atsushi Kinomura; Ryoichi Suzuki; Toshitaka Oka; Yoshinori Kobayashi

doi:10.1103/PhysRevB.75.195404

Evidence for pore surface dependent positronium thermalization in mesoporous silica/hybrid silica films

Chunqing He, Toshiyuki Ohdaira, Nagayasu Oshima, Makoto Muramatsu, Atsushi Kinomura, Ryoichi Suzuki, Toshitaka Oka, Yoshinori Kobayashi

Research output: Contribution to journal › Article › peer-review

45 Citations (Scopus)

Abstract

In this paper, we report the thermalization process of positronium (Ps) in various mesoporous silica/hybrid silica films with pore surfaces decorated by different groups, such as -OH, -H, and - C H3, studied by Ps time-of-flight measurement. Thermalization of Ps in pores with -OH and -H was found to be more efficient than in pores decorated with - C H3. This can be understood from the point of view that Ps thermalization rates upon collisions with these groups are different due to their different effective masses. Therefore, our observation shows that Ps slowing down in mesoporous silica/hybrid silica films is strongly dependent on the pore surface chemistry.

Original language	English
Article number	195404
Journal	Physical Review B - Condensed Matter and Materials Physics
Volume	75
Issue number	19
DOIs	https://doi.org/10.1103/PhysRevB.75.195404
Publication status	Published - 2007 May 2
Externally published	Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics

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Evidence for pore surface dependent positronium thermalization in mesoporous silica/hybrid silica films. / He, Chunqing; Ohdaira, Toshiyuki; Oshima, Nagayasu; Muramatsu, Makoto; Kinomura, Atsushi; Suzuki, Ryoichi; Oka, Toshitaka; Kobayashi, Yoshinori.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 75, No. 19, 195404, 02.05.2007.

Research output: Contribution to journal › Article › peer-review

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AU - Kinomura, Atsushi

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