Preparation And Properties Of Tb³⁺-doped Germanium Borate Magneto-optical Glass

Magneto-optical glass is very competitive in magneto-optical devices due to its advantages of flexible composition,easy size control and drawable optical fiber,but the magneto-optical sensitivity of glass materials still needs to be improved.To solve this problem,taking the Verdet constant of the glass as the main line,Tb₂O₃ doped Ge O₂-B₂O₃-Li₂O-Mg O（GBLM）magneto-optical glass,rare earth oxide co-doped GBLM-Tb₂O₃magneto-optical glass and iron oxide co-doped GBLM-Tb₂O₃ magneto-optical glass were prepared by high temperature melting method in air atmosphere.Physical parameters such as structure,density,optical alkalinity and magneto-optical properties of GBLM glass were tested and analyzed.Specific work contents were as follows:（1）It is found that when the content of Ge O₂ is 40 mol%,the density and Verdet constant of 40Ge O₂-35B₂O₃-3Li₂O-2Mg O-20Tb₂O₃ glass all reach the maximum,which are 4.5275g/cm³ and-73.83 rad/（T·m）,respectively.And the corresponding GBLM glass has a high network tightness as well,thus the optimal matrix ratio is 40Ge O₂-35B₂O₃-3Li₂O-2Mg O-20Tb₂O₃.Subsequently,increasing the concentration of Tb₂O₃shows that when the incident light wavelength is 633 nm,the Verdet constant of 40Ge O₂-15B₂O₃-3Li₂O-2Mg O-40Tb₂O₃glass measured at 298.15 K and 273.15 K is-143.04 rad/（T·m）and-158.56 rad/（T·m）,respectively.（2）It is found that the co-doping of Pr₆O₁₁ has the greatest effect on the Verdet constant of GBLM glass.After co-doping with 1 mol%Pr₆O₁₁,the Verdet constant of GBLM glass increases from-84.40 rad/（T·m）to-85.75 rad/（T·m）.The study on the magneto-optical properties of 40Ge O₂-25B₂O₃-3Li₂O-2Mg O-30Tb₂O₃-z Pr₆O₁₁/Ho₂O₃/Dy₂O₃ glass shows that when the incident light wavelength is 633 nm,and the doping concentration of Pr₆O₁₁,Ho₂O₃ and Dy₂O₃ is 9 mol%,the Verdet constants of 40Ge O₂-25B₂O₃-3Li₂O-2Mg O-30Tb₂O₃-9Pr₆O₁₁/Ho₂O₃/Dy₂O₃ glass are-146.55 rad/（T·m）,-145.80 rad/（T·m）and-143.78rad/（T·m）,respectively.（3）It is found that the structure of GBLM glass is not affected by doping with different concentrations of Fe₂O₃/Fe₃O₄.At 298.15 K,when the incident light wavelength is 633 nm,the Verdet constants of GBLM glass doped with 0.75 mol%Fe₂O₃ and Fe₃O₄ on the basis of30Tb₂O₃ are-92.59 rad/（T·m）and-91.23 rad/（T·m）,respectively.Compared with 40Ge O₂-25B₂O₃-3Li₂O-2Mg O-30Tb₂O₃（-84.40 rad/（T·m））,the values increase by 9.70%and 8.09%,respectively.