The Regulation Technology Of High Temperature Materials' Absorption Characteristics

As the regulation of high temperature materials' absorption characteristics have potential application value in the areas such as radar detection,aerospace,biomedical sciences and solar cells,it has attracted more and more attention that using surface plasmonics effects to regulate metallic materials' absorption characteristics of spectrum.At present,the research on the regulation technology of absorption characteristics confines to silver,gold and other precious metals with a relatively low melting point.Few in the earth's crust and difficult to be exploited,the application of them is limited to some extents.In order to meet the requirements of high temperature environment,this paper studies the regulation technology of high temperature materials' absorption characteristics.Surface plasmonics is an electronic evanescent generated by the interaction between free electrons and photons when the metal surface is under the light.Based on surface plasmonics effects and relevant theory concerning electromagnetic field,this paper studies two periodical nanostructures of ultra high temperature metal materials through the finite difference time domain method(FDTD).Given the various physical phenomena caused by different structural parameters,the author finds out factors regulating absorption characteristics and makes research on absorption mechanism through distribution of electromagnetic field.The main research is carried out as follows:In this paper,the grating periodical nanostructure has been constructed based on the metal tungsten.Then different parameters' impact on characteristics of materials' spectral absorption is simulated and analyzed under wavelength raging from 200 to 4000 nm.The parameters include structural period,width,depth and oxidation film thickness,etc.It is demonstrated that different absorption curves have similar and different optical properties,each of them have absorption peaks with a maximum of over 93%.The dielectric material,period,width and depth of nanostructure are the main factors influencing absorption spectrum,in which,the former two have impact on the wavelength of absorption peaks,with red or blue shifting as parameters change.The findings provide a new method for regulation of high temperature materials' absorption characteristics.The cylindrical periodical nanometer array has been built based on metal tantalum and dielectric material Al2O3.By changing period,cylindrical radius and dielectric materials while keeping other parameters the same as before,the author simulates and calculates spectral absorption curves and makes comparison of similarities and differences of absorption characteristics.As parameters vary,different physical phenomena with different changing rules appear including red shifting,blue shifting of resonance peaks,damping,enhancement and increasing or decreasing bandwidth.Based on distributions of resonance peaks' electric field,two different absorption mechanisms are analyzed,which are the metal surface plasmonics resonance and local waveguide resonance.The findings in this study provide guidance for research on regulation technology concerning spectrum absorption characteristics of ultra-high temperature metal nanostructures.The research of this paper provide new regulating factors for absorption characteristics of subwavelength metal periodic array,enrich the regulation methods of these structures,and facilitate people control electromagnetic wave according to the practical application of need.