Interlaboratory Comparison of Positron Annihilation Lifetime Measurements

Ito, Kenji; Oka, Toshitaka; Kobayashi, Yoshinori; Shirai, Yoshihito; Wada, Kazuhiro; Matsumoto, Megumi; Fujinami, Masanori; Hirade, Tetsuya; Honda, Yoshihide; Hosomi, Hiroyuki; Nagai, Yasuyoshi; Inoue, Koji; Saito, Haruo; Sakaki, Keiji; Sato, K.; Shimazu, Akira; Uedono, Akira

doi:10.4028/www.scientific.net/msf.607.248

Cited by 29 publications

(16 citation statements)

References 2 publications

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“…The time-dependent data of the 1st and 2nd measurement runs were obtained every 45 min under the same conditions as that of DLT. The validity of our lifetime measurements and data analysis was confirmed with certified reference materials (NMIJ CRM 5601-a and 5602-a) provided by the National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST) [10,11]. Positron lifetime spectra were numerically analyzed using the POSITRONFIT code [12].…”

Section: Methodsmentioning

confidence: 62%

Study of reversibility of self-assembly in saponite layered nanoparticles

Numata

Sato

2014

Proc. 2nd Japan-China Joint Workshop on Positron Science

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The reversible process of self-assembly involving the rheological motion of 2-dimensional nanosheets with the aid of water molecules was studied for saponite inorganic layered nanoparticles by dilatometry and positronium lifetime spectroscopy. The two nanosheet insertion type local molecular structure, dominant in the dehydrated state, was not fully reproducible upon dehydration for the self-assembled sample. The two nanosheet insertion type local structure could thus disappear when saponite goes through self-assembly several times. It was furthermore found that a local structure with a void size slightly larger than that in the two nanosheet insertion type structure exists before self-assembly. This structure, presumably due to curved nanosheets, is metastable and gradually disappears during self-assembly.

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Section: Methodsmentioning

confidence: 62%

Study of reversibility of self-assembly in saponite layered nanoparticles

Numata

Sato

2014

Proc. 2nd Japan-China Joint Workshop on Positron Science

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“…The starting samples were exposed to the humidity of ∼35% at the temperature of ∼300 K, where the Ps lifetime spectra were obtained at the time interval of 45-52 min. The validity of our lifetime measurements and data analysis was confirmed with certified reference materials (NMIJ CRM 5601-a and 5602 Technology (AIST) [13,14]. Positron lifetime spectra were numerically analyzed using the POSITRONFIT code [15].…”

Section: Methodsmentioning

confidence: 66%

Self-assembly of saponite nanoparticles originated from nano-layered structure

Sato

Numata

Fujimoto

2013

MATEC Web of Conferences

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Abstract.The mechanism of self-assembly induced by H 2 O molecules is studied for layered saponite nanoparticles and zeolite with the cage structure by means of positronium (Ps) annihilation spectroscopy together with thermogravimetry and differential thermal analysis (TG-DTA). Prior to hydration the saponite exhibits two kinds of open spaces with their sizes of ∼3Å and ∼9Å, whereas open spaces with their sizes of ∼3Å and ∼5Å corresponding to β and α cages are obtained for the zeolite. The occupation of both α and β cages by H 2 O molecules proceeds along with hydration up to 2.5 h, which well synchronizes with the weight gain in TG data. On the contrary, the angstrom-scale open spaces for the saponite vary with hydration in the time scale with ∼100 h much longer than that of TG-DTA with ∼8 h. The present results suggest that the long-term self assembly originates from not the cage but the nanolayered structures.

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“…Positron lifetimes and their relative intensities were numerically determined using the POSITRONFIT code [7]. The validity of our lifetime measurements and data analysis was confirmed with certified reference materials (NMIJ CRM 5601-a and 5602-a) provided by National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST) [8][9]. The magnetic texture of ribbons was investigated by means of transmission Mössbauer spectroscopy (TMS).…”

Section: Methodsmentioning

confidence: 99%