Intensity and composition-dependent sign reversal of non-linearity in TiO_2/CeO_2 nanocomposites  

作　　者：S.Divya V.P.N.Nampoori P.Radhakrishnan A.Mujeeb 

机构地区：[1]International School of Photonics, Cochin University of Science and Technology

出　　处：《Chinese Physics B》2014年第3期298-302,共5页中国物理B（英文版）

基　　金：Project supported by the Department of Science and Technology(DST),Govt.of India

摘　　要：CeO2/TiO2 composite nanoparticles with different Ce/Ti molar ratios have been successfully synthesized via sol-gel method. It was found that the band gap of the nanocomposite is tunable by varying Ce/Ti content. The nonlinear response of the sample was studied by using the nanosecond laser pulses from a Q switched Nd：Yag laser employing the Z-scan method. Open aperture Z-scan experiment revealed that with the increase in the CeO2 amount in the nanocomposite, the non-linearity of the composite increases, and it was assumed that this could be due to the modification of TiO2 dipole symmetry by the addition of CeO2. Closed aperture Z-scan experiment showed that when the CeO2 amount increases, positive nonlinear refraction decreases, and this could be attributed to the increase in the two photon absorption which subsequently suppresses the nonlinear refraction.CeO2/TiO2 composite nanoparticles with different Ce/Ti molar ratios have been successfully synthesized via sol-gel method. It was found that the band gap of the nanocomposite is tunable by varying Ce/Ti content. The nonlinear response of the sample was studied by using the nanosecond laser pulses from a Q switched Nd：Yag laser employing the Z-scan method. Open aperture Z-scan experiment revealed that with the increase in the CeO2 amount in the nanocomposite, the non-linearity of the composite increases, and it was assumed that this could be due to the modification of TiO2 dipole symmetry by the addition of CeO2. Closed aperture Z-scan experiment showed that when the CeO2 amount increases, positive nonlinear refraction decreases, and this could be attributed to the increase in the two photon absorption which subsequently suppresses the nonlinear refraction.

关 键 词：sol-gel method non-linearity Z-scan experiment reversesaturation absorption curve 

分 类 号：TB383.1[一般工业技术—材料科学与工程] O437[机械工程—光学工程]