摘要
Bi nanoparticles embedded in a Si02 matrix were prepared via the high energy ball milling method. The melting behavior of Bi nanopartieles was studied by means of differential scanning calorimetry （DSC） arid high- temperature in situ X-ray diffraction （XRD）. DSC cannot distinguish the surface melting from ＇bulk＇ melting of the Bi nanoparticles. The XRD intensity of the Bi nanopartieles decreases progressively during the in situ heating process. The variation in the normalized integrated XRD intensity versus temperature is related to the average grain size of Bi nanoparticles. Considering the effects of temperature on Debye Waller factor and Lorentz-polarization factor, we discuss the XRD results in accordance with surface melting. Our results show that the in situ XRD technique is effective to explore the surface melting of nanoparticles.
Bi nanoparticles embedded in a Si02 matrix were prepared via the high energy ball milling method. The melting behavior of Bi nanopartieles was studied by means of differential scanning calorimetry （DSC） arid high- temperature in situ X-ray diffraction （XRD）. DSC cannot distinguish the surface melting from ＇bulk＇ melting of the Bi nanoparticles. The XRD intensity of the Bi nanopartieles decreases progressively during the in situ heating process. The variation in the normalized integrated XRD intensity versus temperature is related to the average grain size of Bi nanoparticles. Considering the effects of temperature on Debye Waller factor and Lorentz-polarization factor, we discuss the XRD results in accordance with surface melting. Our results show that the in situ XRD technique is effective to explore the surface melting of nanoparticles.
基金
Supported by the National Natural Science Foundation of China under Grant Nos 11004127 and 51372147, the Shaanxi Province Science and Technology Foundation under Grant No 2012KJXX-30, and the Fundamental Research Funds for the Central Universities under Grant No GK201305006.
