Transparent ceramics are at the heart of modern magneto-optical materials providing promising opportunities for Faraday isolators.1.0 at%RE:Tb3Ga5O12(rare earth(RE)=Pr,Tm,Dy)transparent ceramics were successfully prep...Transparent ceramics are at the heart of modern magneto-optical materials providing promising opportunities for Faraday isolators.1.0 at%RE:Tb3Ga5O12(rare earth(RE)=Pr,Tm,Dy)transparent ceramics were successfully prepared by air sintering and sequential HIP technique using the coprecipitated powders as the raw material.All the powders have shown to be a pure cubic terbium gallium garnet(TGG)phase and exhibit good dispersion.Additionally,a change could not be observed in particle shape with the different doped ions.After the two-step sintering,all the obtained ceramics have good optical quality,and the in-line transmittances at 1070 nm are higher than 80%.Moreover,no secondary phase can be detected from the microstructures.However,the pores which remain entrapped in the ceramics can be noted.The Verdet constant of ceramic samples is optimized by RE doping,and the Verdet constant at 632.8 nm is about−143 rad·T^(−1)·m^(−1),which is about 5%higher than that of TGG ceramics.Finally,the thermo-optical properties of 1.0 at%RE:TGG transparent ceramics are compared.The annealed TGG ceramic showed the best thermo-optical properties,and the thermally induced depolarization of 1.0 at%Ce:TGG and 1.0 at%Tm:TGG was inferior to that of annealed TGG ceramic.展开更多
A new unsymmetrical and noncoplanar diamine containing trifluoromethyl and trimethyl groups, 1,4-bis（4- amino-2-trifluoromethylphenoxy）-2,3,5-trimethylbenzene （2）, was synthesized using 2,3,5-trimethylhydroquinone...A new unsymmetrical and noncoplanar diamine containing trifluoromethyl and trimethyl groups, 1,4-bis（4- amino-2-trifluoromethylphenoxy）-2,3,5-trimethylbenzene （2）, was synthesized using 2,3,5-trimethylhydroquinone and 2-chloro-5-nitrobenzotrifluoride as starting materials. A series of fluorinated poly（ether imide）s （PEIs） （4a-4d） were prepared from diamine 2 with four aromatic dianhydrides via a one-step high-temperature polycondensation procedure. The obtained PEIs were readily soluble in most organic solvents and could be solution-cast into flexible and strong films. The resulting thin films exhibited light color and good optical transparency with a cutoff wave- length of 356--376 nm. They also displayed good thermal stability with glass transition temperatures （Tg） above 281℃, 10% weight loss temperatures in the range of 482--486 ~C, and the weight residue more than 55% at 800℃ in nitrogen. Moreover, they revealed low dielectric constants （2.77-2.93 at 1 MHz） and low moisture absorp- tions （0.41%-0.57%）.展开更多
基金supported by the National Key R&D Program of China(Grant No.2017YFB0310500)the NSFC-RFBR Cooperative Research Project(Grant No.61911530135)+1 种基金the Key Research Project of the Frontier Science of the Chinese Academy of Sciences(No.QYZDB-SSW-JSC022)supported partially by the Ministry of High Education and Science of the Russian Federation and the State Task executed in the Institute of Applied Physics RAS(Project No.00352019-0015)。
文摘Transparent ceramics are at the heart of modern magneto-optical materials providing promising opportunities for Faraday isolators.1.0 at%RE:Tb3Ga5O12(rare earth(RE)=Pr,Tm,Dy)transparent ceramics were successfully prepared by air sintering and sequential HIP technique using the coprecipitated powders as the raw material.All the powders have shown to be a pure cubic terbium gallium garnet(TGG)phase and exhibit good dispersion.Additionally,a change could not be observed in particle shape with the different doped ions.After the two-step sintering,all the obtained ceramics have good optical quality,and the in-line transmittances at 1070 nm are higher than 80%.Moreover,no secondary phase can be detected from the microstructures.However,the pores which remain entrapped in the ceramics can be noted.The Verdet constant of ceramic samples is optimized by RE doping,and the Verdet constant at 632.8 nm is about−143 rad·T^(−1)·m^(−1),which is about 5%higher than that of TGG ceramics.Finally,the thermo-optical properties of 1.0 at%RE:TGG transparent ceramics are compared.The annealed TGG ceramic showed the best thermo-optical properties,and the thermally induced depolarization of 1.0 at%Ce:TGG and 1.0 at%Tm:TGG was inferior to that of annealed TGG ceramic.
基金This work was supported by the National Natural Science Foundation of China （No. 51103016）, the Natural Science Foundation of Jiangsu Province （No. BK2011232 and BK2011241）, the Grant-in-aid for Youth Innovation Fundation of Changzhou University （No. ZMFll020017 and ZMFl102037）, and the Open- ing Project of State Key Laboratory for Modification of Chemical Fibers and Polymer Materials （No. LK1001）.
文摘A new unsymmetrical and noncoplanar diamine containing trifluoromethyl and trimethyl groups, 1,4-bis（4- amino-2-trifluoromethylphenoxy）-2,3,5-trimethylbenzene （2）, was synthesized using 2,3,5-trimethylhydroquinone and 2-chloro-5-nitrobenzotrifluoride as starting materials. A series of fluorinated poly（ether imide）s （PEIs） （4a-4d） were prepared from diamine 2 with four aromatic dianhydrides via a one-step high-temperature polycondensation procedure. The obtained PEIs were readily soluble in most organic solvents and could be solution-cast into flexible and strong films. The resulting thin films exhibited light color and good optical transparency with a cutoff wave- length of 356--376 nm. They also displayed good thermal stability with glass transition temperatures （Tg） above 281℃, 10% weight loss temperatures in the range of 482--486 ~C, and the weight residue more than 55% at 800℃ in nitrogen. Moreover, they revealed low dielectric constants （2.77-2.93 at 1 MHz） and low moisture absorp- tions （0.41%-0.57%）.
