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.
|Number of pages||6|
|Journal||Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan|
|Publication status||Published - 2009|
- Cu nano precipitate
- Positron annihilation.
- Size estimation
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Metals and Alloys
- Materials Chemistry