| Yttrium iron garnet(Y3Fe5O12,YIG)polycrystalline had been synthesized by co-precipitation method and solid-phase reaction method in this paper.The polycrystalline materials was tested and analyzed,then the coprecipitation method was optimized to be the primary method.The polycrystalline material rod with uniform composition and dense was made by isostatic pressure and secondary sintering processes.YIG crystals were grown by optical floating zone method,and the affecting factors of crystal growth were analyzed in detail.Finally,the optimal process for crystal growth was determined.Furthermore,the rare earth Ce3+ions were doped in the YIG crystal to improve the magneto-optical properties,and the doping concentration is x=0.05-0.25.The as-grown YIG and Ce:YIG crystals were cut and polished.Then the X-Ray powder diffraction,infrared spectroscopy,Raman spectroscopy and transmittance were tested.The test results show that YIG crystal has high purity and the transmittance is85%.As for Ce:YIG crystals,when Ce concentration is 0.05-0.15,the crystals have a high purity.However,the CeO2 heterophase was generated from 0.2 to 0.25.The transmittance of Ce:YIG crystal at the doping concentration of 0.05-0.15 is 35%,45%,26%,respectively.The magnetic properties of the crystals were tested by PPMS.The results indicate that the saturation magnetization decreases with the concentration of Ce3+ions increases.The Verdet constants of YIG and Ce:YIG crystals were measured by using a self-made Faraday test system.The Verdet constants of YIG crystals at wavelength of 808 nm,980 nm,and 1310 nm are-476.6898rad·T-1·m-1,-211.6157rad·T-1·m-1,-108.3139rad·T-1·m-1,respectively.The Verdet constant of CexY3-xFe5O12?x=0.05-0.15?crystals at 1310 nm are-486.011rad/T·m,-827.428rad/T·m,-1223.191rad/T·m,respectively.Thetime-domainand frequency-domain spectra of YIG and Ce:YIG crystals were analyzed for the first time,and the corresponding optical parameters such as refractive index and absorption coefficient were extracted. |
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