Spectroscopic Ellipsometry Under High Pressure Loaded By Diamond Anvil

Diamond anvil Cell is an universal equipment widely used in modern high-pressure researches.Compared with heavy large-scale high-pressure equipment,it has the advantages of higher pressure,easy to achieve experimental conditions,and simple operation.Due to the good optical transparency of diamond,spectroscopic ellipsometry,as a high-precision and non-destructive photoelectric measurement technology,is expected to become an effective measurement method for high-pressure material under diamond anvil loading.Aiming at the unique challenge of diamond anvil loading process measurement,this thesis work on the research of high-pressure diamond anvil loading process measurement method based on spectroscopic ellipsometry.The specific contents include:(1)The optical path of high-pressure ellipsometry is designed,and the optical model of the material under high-pressure loading is established around the high-pressure loading interface.The corresponding data processing and analysis methods are proposed.(2)On the basis of the existing ellipsometer,the ellipsometry measuring device for the loading process of diamond anvil is designed and built,and the load calibration of the experimental device based on ruby fluorescence spectrum pressure calibration method is completed,and then the relationship between the anvil locking torque and the loading pressure is established;The analysis and calibration of the convergent lens effect are completed,which effectively reduces the measurement error caused by defocusing.(3)The influence of diamond on ellipsometry parameters was obtained by characterization of diamond anvil cell,and the measurement unit calibration of experimental device based on silica standard sample was completed,which verified the optical characteristic model of high-pressure ellipsometry proposed in this paper.Through the experiment of high pressure loading measurement on iron,the measurement method and experimental device proposed in this paper are verified.The theoretical and experimental methods proposed in this paper will broaden the application range of ellipsometry and enrich the measurement methods of diamond materials under high pressure loading.