Synthesis And Nonlinear Optical Properties Of Tungsten Carbide/Molybdenum Carbide Nanocomposites

Nano materials have some more diversified characteristics that are different from those of bulk materials due to its surface effect and small size effect.Through the regulation of size and morphology,the intrinsic properties of nano-structured materials can be adjusted.Therefore,they have attracted extensive attention and have been deeply studied by scholars in application.The nonlinear optics of nanomaterials is also a hot topic in 21 th century.The study of nanomaterials with different types and morphologies has broad application prospects in optical communication,optical protection,optical detection and optical devices.Transition metal carbide materials with its excellent physical and chemical characteristics,such as high melting point,high conductivity,good chemical stability,diverse electronic structure,etc.,have been more in-depth exploration in electronics,catalysis,energy,photonics,machinery and other scientific research.This dissertation mainly studies the third-order nonlinear optical absorption characteristics of tungsten and molybdenum carbide nanomaterials in VI-B element clusters.The main research contents are as follows:Tungsten oxide,tungsten oxide/molybdenum oxide composite nanomaterials were synthesized by hydrothermal method.Carbide precursor was synthesized by hydrothermal synthesis of oxide material and glucose.The organic glass with nanomaterials was prepared by using methyl methacrylate(MMA)as the carrier.The morphology and spectral absorption characteristics of the material were characterized by electron scanning microscope and ultraviolet visible light spectrometer respectively.The results show that the morphology and size of the two materials are relatively uniform.Tungsten carbide nanomaterials exist in the form of nanoparticles while tungsten carbide/molybdenum carbide nanocomposites exist in the form of rods.The transmittance of visible light found in relatively high levels.The open z-scan technique was used to perform nonlinear optical test made upon.Both pure WC nanoparticles and tungsten carbide/molybdenum carbide nanorods have the characteristics of conversion from saturation absorption to reverse saturation absorption.Due to the complex excited state transition,the saturation intensity of pure WC was increases with the increase of energy,while the nonlinear absorption coefficient decreases.Tungsten carbide/molybdenum carbide composites exhibit stronger nonlinear absorption characteristicsin the process of increasing the input energy.The energy level transition theory is used to analyse pure tungsten carbide and carbide composites.Nanocomposites have better properties,and the third-order nonlinear absorption coefficient increases with the increase of energy,which has better application value in high-energy laser protection.