Study On Preparation And Optical Properties Of Fe,Gd/MgO Nanocomposite Composite Film

MgO is a wide band gap material with good transmittance in the band of 300-2500 nm.MgO optical windows are widely used in aerospace,optoelectronic devices and other fields.If it is to be used in space detectors,the transmittance of MgO optical windows needs to be further improved.Based on this,in order to develop high performance,wide band MgO wide spectrum optical windows,relevant research has been carried out.The research results are as follows:(1)Fe nanoparticles(NPs),Gd NPs and Fe,Gd mixed NPs were embedded in homogeneous epitaxial single crystal MgO films by pulsed laser vapor deposition(PLD).And a series of metal nanocomposite films were prepared.(2)The structure,morphology and composition of the films were characterized by XRD,AFM,SEM,TEM and XPS.The analysis shows that Fe NPs,Gd NPs and Fe,Gd mixed NPs are uniformly embedded in MgO films.In MgO thin films,Fe NPs are oblate hexagonal and Gd NPs are irregular polygon,and their sizes are less than 10 nm.The embedded metal nanoparticles in MgO are partially oxidized and have a core-shell structure.At the same time,metal NPs and MgO films form sub-wavelength microstructures.(3)The composite films were analyzed by UV-Vis Spectrometer.It is found that embedded Fe NPs in MgO films achieve the near-infrared antireflection in the range of 190 nm-235 nm.Embedded Gd NPs in MgO films achieve the deep UV narrow band antireflection in the range of 1000 nm-2500 nm.By embedding Fe and Gd NPs simultaneously,MgO achieved wide-spectrum antireflection in the range of 190 nm-235 nm and 300 nm-2500 nm.Combined with the equivalent medium theory and ellipsometry,it is found that the sub-wavelength microstructure is formed between metal nanoparticles and MgO films.This structure is an equivalent dielectric antireflection film,thus realizing the antireflection of MgO.(4)Finally,the absorption and fluorescence spectra of Fe,Gd/MgO nanocomposite films were analyzed.It was found that there were a large number of oxygen vacancies in the films.It is also found that metal NPs produce plasmon resonance absorption effect.Fe,Gd/MgO nanocomposite films were successfully prepared by PLD in this paper.The transmission band of MgO was successfully extended from 300-2500 nm to 190 nm-2500 nm.At the same time,the transmittance of MgO in 300 nm-2500 nm band is increased by3.5%,and the wide-spectrum antireflection of MgO is realized.