Polycrystalline diamond(PCD) films 100 mm in diameter are grown by 915 MHz microwave plasma chemical vapor deposition(MPCVD) at different process parameters,and their thermal conductivity(TC) is evaluated by a laser f...Polycrystalline diamond(PCD) films 100 mm in diameter are grown by 915 MHz microwave plasma chemical vapor deposition(MPCVD) at different process parameters,and their thermal conductivity(TC) is evaluated by a laser flash technique(LFT) in the temperature range of230-380 K.The phase purity and quality of the films are assessed by micro-Raman spectroscopy based on the diamond Raman peak width and the amorphous carbon(a-C) presence in the spectra.Decreasing and increasing dependencies for TC with temperature are found for high and low quality samples,respectively.TC,as high as 1950 ± 230 W m^(-1) K^(-1) at room temperature,is measured for the most perfect material.A linear correlation between the TC at room temperature and the fraction of the diamond component in the Raman spectrum for the films is established.展开更多
基金supported by the Russian Ministry of Education and Science(RMES),Agreement No.14.613.21.0021,unique ID No.RFMEFI61314X0021the Department ofScience & Technology(DST),India,grant No.GAP0246 under the joint RMES-DST Research Collaboration Agreement 'Development of large size polycrystalline CVD diamond material for optical windows and support rods in high power microwave tubes'
文摘Polycrystalline diamond(PCD) films 100 mm in diameter are grown by 915 MHz microwave plasma chemical vapor deposition(MPCVD) at different process parameters,and their thermal conductivity(TC) is evaluated by a laser flash technique(LFT) in the temperature range of230-380 K.The phase purity and quality of the films are assessed by micro-Raman spectroscopy based on the diamond Raman peak width and the amorphous carbon(a-C) presence in the spectra.Decreasing and increasing dependencies for TC with temperature are found for high and low quality samples,respectively.TC,as high as 1950 ± 230 W m^(-1) K^(-1) at room temperature,is measured for the most perfect material.A linear correlation between the TC at room temperature and the fraction of the diamond component in the Raman spectrum for the films is established.
