A New Method for Size Estimation of Cu Nano-precipitates in Fe Based on Positron Quantum-dot Confinement

作者：Toyama Takeshi^*; Nagai Yasuyoshi; Tang Zheng; Inoue Koji; Chiba Toshinobu; Hasegawa Masayuki; Ohkubo Tadakatsu; Hono Kazuhiro

来源：Journal of the Iron and Steel Institute of Japan, 2009, 95(2): 118-123.

DOI：10.2355/tetsutohagane.95.118

• Cu nano precipitate
• size estimation
• positron annihilation

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 degrees 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.

• 出版日期2009-2
• 单位华东师范大学