A new method for size estimation of cu nano-precipitates in fe based on positron quantum-dot confinement

Takeshi Toyama, Yasuyoshi Nagai, Zheng Tang, Koji Inoue, Toshinobu Chiba, Masayuki Hasegawa, Tadakatsu Ohkubo, Kazuhiro Hono

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2 Citations (Scopus)


Synapsis : A new method for size estimation of Cu (sub)nano-precipitates in Fe based on a positron quantum-dot-state is developed. Utilizing a unique characteristic of the positron quantum-dot confinement in positron affinitive embedded nano-precipitates, the smearing of the momentum distribution of positron-electron pair around the Fermi momentum in the Cu nano-precipitates is observed by two-dimensional angular correlation of positron annihilation radiation (2D-ACAR) measurements. Due to the uncertainly relation between position and momentum, the size of the Cu nano-precipitates is estimated from the width of the momentum smearing which is inversely proportional to the average size of the precipitates where positrons are confined. Fe-Cu alloys were aged at 475°C for 0.1 to 20 h to form the Cu nano-precipitates with various sizes. The sizes estimated from 2D-ACAR are compared with those by three-dimensional atom probe (3D-AP). Both the results agree with each other. Furthermore, the present method gives the sizes of the Cu subnano-precipitates which are too small to be detected even by the other technique, such as 3D-AP.

Original languageEnglish
Pages (from-to)118-123
Number of pages6
JournalTetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan
Issue number2
Publication statusPublished - 2009


  • Cu nano precipitate
  • Positron annihilation.
  • Size estimation

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Metals and Alloys
  • Materials Chemistry


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