壓力作用下幾種納米材料的性質(zhì)研究.pdf

1、中國(guó)科學(xué)技術(shù)大學(xué)碩士學(xué)位論文壓力作用下幾種納米材料的性質(zhì)研究姓名：程思申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：凝聚態(tài)物理指導(dǎo)教師：張?jiān)雒?丁澤軍20100524ABSTRACTABSTRACTThe high pressure science is an important field in modern science and technology.As another parameter in addition to temperature and

2、 consititute, Pressure affects var-ious properties of materials to a large extent. It can reveal new phenomenons whichcan not be obtained at normal condition, furthermore, new phases and new substancecould be found throu

3、gh high pressure studies. It also gives a new perspective to explainthe characters of material and phenomenons at ambient pressure. In-situ high pressureraman spectroscopy is one of the major techniques in high pressure

4、science. Detailedinformation such as phonon spectra, electron-phonon interaction and anharmonic ef-fect on lattice vibration at pressure could be obtained from Raman Spectra recordedunder high pressure condition, and hig

5、h pressure raman spectroscopy can be used toinvestigate phase transition. Compared to corresponding bulk materials, nanomaterialshave the specific properties such as the small size effects, confinement effects and grainb

6、oundary effects. Nanomaterials often manifest different physical and chemical proper-ties compared to the corresponding bulk materials under high pressure condition, whichmakes it most likely to found new phases and new

7、materials. In this thesis, we usedhigh pressure technique to research on the phase transition of several nanomaterials,the main work contains:Chapter One briefly introduce nanomaterials and nanotechnology. It also gives

8、ashort summary of the high pressure technique and high pressure research methods inour laboratory.In Chapter Two, we investigate the phase transition of a direct band gap semi-conductor: Zinc Selenide(ZnSe), with the Mor

9、phologies of hollow spheres by nanorodarray and hollow spheres by nanobelt array. For the ZnSe hollow spheres by nanorodarray, we found a phase transition from Zinc blende to Cinnabar at about 9.8 GPa. Itthen transforms

10、to Rocksalt at 11.4 GPa, and the whole process is completed at about 18GPa. A disappearance of external modes suggests that the sample undergoes a phasetransition to amorphous at about 20 GPa. We did not find any signal

11、which shows aphase transition from phase transition from Zinc blende to Cinnabar with the Ramanspectroscopy records of ZnSe hollow spheres by nanobelt array. The sample transformsto Rocksalt directly at about 11.4 GPa an