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Erdong LU and Pengshou XU(Hefei National Synchrotron Radiation Lab. , University of Science and Technology of China , Hefei , 230026 , China)Mingrong JI , Maosheng MA and Xianming LIU(Structure Research Lab. , University of Science and Technology of China , Hefe
材料科学技术（英）
The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.
关键词:
Qijin ZHANG , Wenying XU , and Zhiyong WANG (Dept. of Mater. Sci. & Eng. , University of Science and Technology of China , Hefei , 230026 , China)(To whom correspondence should be addressed)(Dept. of Modern Chemistry , University of Science and Technology of Ch
At 225℃. caprolactone has been polymerized in the presence of succinic acid under dry nitrogen atmosphere. Characterizations of the polymer through IR and molecular weight measurements by 1H-NMR and end group titration have shown that the polycaprolactone obtained is of two carboxyl end groups. The molecular weight of it increases with decreasing of the acid content in the reaction mixture under the same polymerization conditions. With a certain ratio of acid to caprolactone. the maximum of molecular weight of the polymer will be reached at the reaction time of 3h.
