Preparation And Characterization Of Nickel Photonic Crystals

Photonic crystal is made by the dielectrics which are arranged periodically. It has two features which are photonic band gap and the density of state. We can use these features to control the reflection, absorption and filtering of light. Currently in the field of light and heat, photonic crystals have been some applications, such as one-dimensional photonic crystal used for TBC, which is made by the metal or metal oxide arranged periodically in one direction; two-dimensional, three-dimensional photonic crystal because of its regulating thermal radiation properties used in thermal solar technology. More and more scholars has been paying attentions to the applications of photonc crystals on the field of light and heat.Because of the non-continuity of the metal dielectric, Metallic photonic crystal is easier to obtain complete PBG, and can use its band-edge radiation to enhance the radiation of electromagnetic wave. We study the fabrication of three-dimensional metallic photonic crystals, their mechanical properties and the resistance of high temperature performance so that we can explore whether photonic crystals can be used for thermal protection system.Firstly, highly ordered metallic photonic crystal has been fabricated by using electrodeposition combined with colloidal crystal template method. SEM, FFT, XRD, EDX were used to characterize the structure, components and the degree of order of photonic crystals; The optical properties of photonic crystals show that the nickel photonic crystal has weak surface plamons effect which is the combination of Bragg Plasmon and Mie Plasmon ,and cut-off frequency.Secondly, the mechanical properties of metallic photonic crystals have been studied by using berkovich tips and punch. Berkovich tip with blunted tip is used to study the hardness and modulus with the increase of indentation depth and annealing temperature. Sharp berkovich indenter tip is used to study the ability to resist deformation and failure of photonic crystal with the size of the pore increasing. When the sample occurs oxidation at 650℃, there has been NiO layer, resulting in strength reducing. By comparing calculated value with experimental value, Minimum solid area model is suitable for photonic crystal.The deformation mechanisms of the wall which are the shear, bending and collapse, and the emerge of shear bands by using flat punch. Compared experimental values with theoretical calculations by using Gibson-Ashaby model, the hardness has agreement, but the modulus has not. The substrate has great effect on modulus leading to the composite modulus.Thirdly, the thermal performances such as thermal stability and thermal shock resistance of photonic crystals are analyzed. The results show that photonic crystal has good thermal stability. There are little cracks observed using SEM when the thermal shocks occur at 300 and 400℃which verifies good performance of thermal shock resistance.Finally,Silicon carbide is prepared by using Pulsed Laser Deposition on the surface of photonic crystals. The results from XPS and XRD confirme the formation of silicon carbide. Then the emisivity of the composite structure is measured which confirms that the photonic crystal has effect on emissivity .