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Optimized Copper Distribution and Enhanced Coercivity in PrO2-Doped Sm2Co17-Type Magnets 认领 引用
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作者 Qi-Qi Yang Jun Li +3 位作者 Yu-Cheng Hu Xiao-Yu Zhu Tao Yuan Ying Liu 《Rare Metals》 SCIE EI CAS CSCD 2026年第1期237-250,共14页
A rational design of Cu distribution is crucial for achieving optimal magnetic properties in Sm2Co17-type magnets.In this study,nanostructured PrO2 powders were employed to induce Cu redistribution at grain b... A rational design of Cu distribution is crucial for achieving optimal magnetic properties in Sm2Co17-type magnets.In this study,nanostructured PrO2 powders were employed to induce Cu redistribution at grain boundaries while preserving the cellular microstructure.The corresponding coercivity(Hcj),remanence(Br),and maximum energy product((BH)max) were significantly enhanced in the 1 wt% PrO2-doped magnet,with improvements of 4.36 kOe,0.22 kGs and 1.1 MGOe,respectively.These results surpass those of most rare-earth-oxide-doped Sm2Co17-type magnets reported to date.Microstructure characterization and micromagnetic simulations confirm that the coarse Cu-rich phase induced by PrO2 doping enhances the pinning strength at grain boundaries,thereby contributing to the observed coercivity enhancement.The(Sm1-xPrx)2Co17 phase exhibits a higher substitution energy barrier at Co sites,which promotes Cu migration toward grain boundaries.Meanwhile,the(Sm1-xPrx)2Co17phase also slightly improves the remanence in the 1 wt% PrO2-doped magnet due to its higher saturation magnetization(Ms).However,excessive PrO2 doping(2 wt%),while further increasing coercivity by 6.45 kOe,adversely affects squareness and remanence.This study demonstrates a viable strategy for fabricating high-performance Sm2Co17-type permanent magnets while enabling efficient utilization of rare-earth Pr oxides. 展开更多
关键词 cellular structure Cu migration PrO2-doping Sm2Co17-type magnets
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Grain boundary engineering of CeO2 induced electron redistribution for dimethyl carbonate synthesis from CO2 认领 引用
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作者 Guoqiang Hou Di Xu +3 位作者 Haifeng Fan Yangyang Li Siyi Huang Mingyue Ding 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2026年第1期316-329,共14页
Direct synthesis of dimethyl carbonate(DMC)from CO2 is critical for achieving carbon neutrality,yet the sluggish formation and conversion of the key*CH₃OCOO intermediate-due to the difficulty of C-O coupling-limit ... Direct synthesis of dimethyl carbonate(DMC)from CO2 is critical for achieving carbon neutrality,yet the sluggish formation and conversion of the key*CH₃OCOO intermediate-due to the difficulty of C-O coupling-limit high DMC yields.Herein,we developed a boric acid-assisted recrystallization strategy to fabricate grain-boundary-rich CeO2 hollow nanospheres,which serve as an efficient catalyst for CO2 to DMC synthesis.The introduction of grain-boundary(GBs)induced the electron redistribution,which led a decrease in the electron density of bulk Ce ions and created a localized electron-rich region at homogeneous interface.This unique electronic landscape promoted reactive methoxy formation and stronger CO2 adsorption,thereby enabling more efficient coupling of*CH3O and*CO2 to form the*CH3OCOO.Concurrently,the enhanced CO2 adsorption facilitated the dissociation of*CH3OCOO and subsequent DMC formation.As a result,the 4%BCeO2-GBs achieved an advantageous DMC yield of 19.8 mmol/g.In the assistance of dehydrating agent,the catalyst delivered a remarkable 264.2 mmol/g DMC yield and 7.12%methanol conversion,which was 32 times higher than commercial CeO2.This study elucidated the intrinsic mechanisms governing*CH3OCOO intermediate behavior and offers valuable guidance for CO2 converting into high-value organic chemicals. 展开更多
关键词 Dimethyl carbonate synthesis CeO2 catalyst Grain boundary engineering Electron redistribution Reaction intermediates
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Engineering of sulfate ions migration in Fe2O3-doped NiSO4/Al2O3 catalysts to enhance the selective trimerization of propylene 认领 引用
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作者 Xu Liu Yu Ling +1 位作者 Xiao Chen Changhai Liang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2025年第5期376-391,共16页
Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of pro... Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of products is profoundly influenced by the catalyst structure.In this study,Fe2O3-doped NiSO4/Al2O3 catalysts have been meticulously developed to facilitate the selective trimerization of propylene under mild conditions.Significantly,the 0.25Fe2O3-NiSO4/Al2O3 catalyst demonstrates an enhanced reaction rate(48.5 mmolC3/(gcat.·h)),alongside a high yield of C9(~32.2%),significantly surpassing the performance of the NiSO4/Al2O3 catalyst(C9:~24.1%).The incorporation of Fe2O3 modifies the migration process of sulfate ions,altering the Lewis acidity of the electron-deficient Ni and Fe sites on the catalyst and resulting a shift in product distribution from a Schulz-Flory distribution to a Poisson distribution.This shift is primarily ascribed to the heightened energy barrier for theβ-H elimination reaction in the C6 alkyl intermediates on the doped catalyst,further promoting polymerization to yield a greater quantity of Type II C9.Furthermore,the validation of the Cossee-Arlman mechanism within the reaction pathway has been confirmed.It is noteworthy that the 0.25Fe2O3-NiSO4/Al2O3 catalyst exhibits remarkable stability exceeding 80 h in the selective trimerization of propylene.These research findings significantly enhance our understanding of the mechanisms underlying olefin oligomerization reactions and provide invaluable insights for the development of more effective catalysts. 展开更多
关键词 Propylene trimerization Fe2O3-doped NiSO4/Al2O3catalyst Sulfate ions migration Poisson distribution Cossee-Arlman mechanism
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Developing sodium-doped ceria-based electrolytes for low-temperature solid oxide fuel cells 认领 引用
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作者 Qi An Ruyi Hou +5 位作者 Xinchao Mei Muhammad Afzal Wenjing Dong Baoyuan Wang Xunying Wang Chen Xia 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2026年第6期2055-2068,I0046-I0052,共14页
Na-doped CeO2(NDC)electrolytes with 0.05,0.10,0.15,and 0.20 molar ratios of Na ions(0.05NDC,0.1NDC,0.15NDC,and 0.2NDC)were synthesized and systematically evaluated for low-temperature solid oxide fuel cell(SOFC)app... Na-doped CeO2(NDC)electrolytes with 0.05,0.10,0.15,and 0.20 molar ratios of Na ions(0.05NDC,0.1NDC,0.15NDC,and 0.2NDC)were synthesized and systematically evaluated for low-temperature solid oxide fuel cell(SOFC)applications.Density function-al theory(DFT)calculations reveal that Na doping lowers the oxygen-vacancy formation energy.Structural analysis confirms progressive lattice expansion in NDCs and a maximum oxygen-vacancy concentration in 0.15NDC,while incomplete incorporation of Na in 0.2NDC yields residual Na2CO3.Conductivity studies demonstrate negligible electronic conductivity and a peak ionic conductivity in 0.15NDC,suggesting that moderate Na doping enhances ionic transport,whereas excessive dopant is detrimental.Two 0.15NDC-based SOFCs are fabricated by ceramic and dry-pressing methods,and their maximum power densities at 550°C are 208 and 778 mW·cm−2,respectively,indicating the rapid ionic transport of the 0.15NDC electrolyte.These results demonstrate that Na doping is an effective route for develop-ing advanced low-temperature SOFC electrolytes. 展开更多
关键词 solid oxide fuel cells Na-doped CeO2 electrolyte oxygen vacancy ionic conductivity high performance
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Fabrication of Gd2O3-doped CeO2thin films through DC reactive sputtering and their application in solid oxide fuel cells 认领 引用 被引量：5
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作者 Fuyuan Liang Jiaran Yang +1 位作者 Haiqing Wang Junwei Wu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第6期1190-1197,共8页
Physical vapor deposition(PVD)can be used to produce high-quality Gd2O3-doped CeO2(GDC)films.Among various PVD methods,reactive sputtering provides unique benefits,such as high deposition rates and easy upscalin... Physical vapor deposition(PVD)can be used to produce high-quality Gd2O3-doped CeO2(GDC)films.Among various PVD methods,reactive sputtering provides unique benefits,such as high deposition rates and easy upscaling for industrial applications.GDC thin films were successfully fabricated through reactive sputtering using a Gd0.2Ce0.8(at%)metallic target,and their application in solid oxide fuel cells,such as buffer layers between yttria-stabilized zirconia(YSZ)/La0.6Sr0.4Co0.2Fe0.8O3−δand as sublayers in the steel/coating system,was evaluated.First,the direct current(DC)reactive-sputtering behavior of the GdCe metallic target was determined.Then,the GDC films were deposited on NiO-YSZ/YSZ half-cells to investigate the influence of oxygen flow rate on the quality of annealed GDC films.The results demonstrated that reactive sputtering can be used to prepare thin and dense GDC buffer layers without high-temperature sintering.Furthermore,the cells with a sputtered GDC buffer layer showed better electrochemical performance than those with a screen-printed GDC buffer layer.In addition,the insertion of a GDC sublayer between the SUS441 interconnects and the Mn-Co spinel coatings contributed to the reduction of the oxidation rate for SUS441 at operating temperatures,according to the area-specific resistance tests. 展开更多
关键词 solid oxide fuel cell physical vapor deposition Gd2O3-doped CeO2 metallic interconnects electrical conductivity
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Supercritical water syntheses of transition metal-doped CeO_2 nano-catalysts for selective catalytic reduction of NO by CO:An in situ diffuse reflectance Fourier transform infrared spectroscopy study 认领 引用 被引量：17
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作者 Xiaoxia Dai Weiyu Jiang +4 位作者 Wanglong Wang Xiaole Weng Yuan Shang Yehui Xue Zhongbiao Wu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第4期728-735,共8页
In the present study,we synthesized CeO2 catalysts doped with various transition metals(M=Co,Fe,or Cu)using a supercritical water hydrothermal route,which led to the incorporation of the metal ions in the CeO2 lattice... In the present study,we synthesized CeO2 catalysts doped with various transition metals(M=Co,Fe,or Cu)using a supercritical water hydrothermal route,which led to the incorporation of the metal ions in the CeO2 lattice,forming solid solutions.The catalysts were then used for the selective catalytic reduction(SCR)of NO by CO.The Cu‐doped catalyst exhibited the highest SCR activity;it had a T50(i.e.,50%NO conversion)of only 83°C and a T90(i.e.,90%NO conversion)of 126°C.Such an activity was also higher than in many state‐of‐the‐art catalysts.In situ diffuse reflectance Fourier transform infrared spectroscopy suggested that the MOx‐CeO2 catalysts(M=Co and Fe)mainly followed an Eley‐Rideal reaction mechanism for CO‐SCR.In contrast,a Langmuir‐Hinshelwood SCR reaction mechanism occurred in CuO‐CeO2 owing to the presence of Cu+species,which ensured effective adsorption of CO.This explains why CuO‐CeO2 exhibited the highest activity with regard to the SCR of NO by CO. 展开更多
关键词 Supercritical water Nitrogen oxides CO Selective catalytic reduction Diffuse reflectance Fourier transform infrared spectroscopy CeO2
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Preparation and characterization of Cu-doped mesoporous CeO_2 for CO oxidation 认领 引用 被引量：2
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作者 田俊杰 纳薇 +1 位作者 王华 高文桂 《Journal of Central South University》 SCIE EI CAS 2014年第2期482-486,共5页
Mesoporous CeO2 was first synthesized by hydrothermal method,and then used to synthesize different contents of CuO)x/CeO2(x:molar ratio of Cu to Ce) by deposition-precipitation method.These materials were characterize... Mesoporous CeO2 was first synthesized by hydrothermal method,and then used to synthesize different contents of CuO)x/CeO2(x:molar ratio of Cu to Ce) by deposition-precipitation method.These materials were characterized by X-ray diffraction(XRD),N2 adsorption and desorption,H2 temperature programmed reduction(H2-TPR) and O2 temperature programmed desorption(O2-TPD) to study the crystal structure,surface area,and the mechanism of CO oxidation.The results show that,on XRD patterns,no evidence of CuO diffraction peaks is present until Cu loading is increased to 20%.The BET surface area decreases noticeably with the increase of Cu content.Compared with other samples,the better reducibility and activity oxygen species of(CuO)10%/CeO2coincide with its better catalytic activity. 展开更多
关键词 mesoporous CeO2 catalytic activity CuO/CeO2 CO oxidation
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Morphology and crystal-plane effects of Zr-doped CeO2 nanocrystals on the epoxidation of styrene with tert-butylhydroperoxide as the oxidant 认领 引用 被引量：3
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作者 Jia Ren Xin Liu +1 位作者 Ruihua Gao Wei-Lin Dai 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第4期681-687,共7页
The morphology effect of Zr-doped CeOwas studied in terms of their activities in the selective oxidation of styrene to styrene oxide using tert-butyl hydroperoxide as the oxidant. In the present work, Zrdoped CeOnanor... The morphology effect of Zr-doped CeOwas studied in terms of their activities in the selective oxidation of styrene to styrene oxide using tert-butyl hydroperoxide as the oxidant. In the present work, Zrdoped CeOnanorods exhibited the highest catalytic performance（yield of styrene oxide and TOF value）followed by nanoparticles and nanocubes. For the Zr-doped CeOnanorods, the apparent activation energy is 56.3 k J/mol, which is much lower than the values of catalysts supported on nanoparticles and nanocubes（73.3 and 93.4 k J/mol）. The high resolution transmission electron microscopy results indicated that（100） and（110） crystal planes are predominantly exposed for Zr-doped CeOnanorods while（100）and（111） for nanocubes,（111） for nanoparticles. The remarkably increased catalytic activity of the Zrdoped CeOnanorods is mainly attributed to the higher percentage of Cespecies and more oxygen vacancies, which are associated with their exposed（100） and（110） crystal planes. Furthermore, recycling studies proved that the heterogeneous Zr-doped CeOnanorods did not lose its initial high catalytic activity after five successive recycles. 展开更多
关键词 Morphology effect Zr-doped CeO2 Styrene Selective oxidation Oxygen vacancies
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Ln3+(Ln=Eu,Dy)-doped Sr2CeO4 fine phosphor particles:Wet chemical preparation,energy transfer and tunable luminescence 认领 引用 被引量：7
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作者 Na Gao Yanfei Yang +4 位作者 Shikao Shi Jiye Wang Shuping Wang Jibiao Li Lianshe Fu 《Journal of Rare Earths》 SCIE EI CAS CSCD 2020年第12期1273-1280,共8页
The Sr2 CeO4:Ln3+(Ln=Eu,Dy)fine phosphor particles were prepared by a facile wet chemical approach,in which the consecutive hydrothermal-combustion reaction was performed.The doping of Ln3+into Sr2 CeO4 has little inf... The Sr2 CeO4:Ln3+(Ln=Eu,Dy)fine phosphor particles were prepared by a facile wet chemical approach,in which the consecutive hydrothermal-combustion reaction was performed.The doping of Ln3+into Sr2 CeO4 has little influence on the structure of host,and the as-prepared samples display wellcrystallized spherical or elliptical shape with an average particle size at about 100-200 nm.For Eu3+ions-doped Sr2 CeO4,with the increase of Eu3+-doping concentration,the blue light emission band with the maximum at 468 nm originating from a Ce4+→O2-charge transfer of the host decreases obviously and the characteristic red light emission of Eu3+(5 D0→7 F2 transition at 618 nm)is enhanced gradually.Simultaneously,the fluorescent lifetime of the broadband emission of Sr2 CeO4 decreases with the doping of Eu3+,indicating an efficient energy transfer from the host to the doping Eu3+ions.The ene rgy transfer efficiency from the host to Eu3+was investigated in detail,and the emitting color of Sr2 CeO4:Eu3+can be easily tuned from blue to red by varying the doping concentration of Eu3+ions.Moreover,the luminescence of Dy3+-doped Sr2 CeO4 was also studied.Similar energy transfer pheno menon can be observed,and the incorporation of Dy3+into Sr2 CeO4 host leads to the characteristic emission of 4 F9/2→6 H15/2(488 nm,blue light)and 4 F9/2→6 H13/2(574 nm,yellow light)of Dy3+.The Sr2 CeO4:Ln3+fine particles with tunable luminescence are quite beneficial for its potential applications in the optoelectronic fields. 展开更多
关键词 Wet chemistry preparation Sr2CeO4 Ln3+ion Phosphor Luminescence Energy transfer
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Synthesis and Catalytic Performance of a New V-doped CeO2-supported Alkali-activated-steel-slag-based Photocatalyst 认领 引用 被引量：5
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作者 KANG Le DU Huiling +3 位作者 DENG Jun JING Xinrui ZHANG Sen ZNANG Yaojun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2021年第2期209-214,共6页
A novel V-doped CeO2-supported alkali-activated-steel-slag-based catalyst(V-CeO2/AC)for photocatalytic decomposition of water to hydrogen was prepared via co-impregnation method.The chemical composition,mineral ... A novel V-doped CeO2-supported alkali-activated-steel-slag-based catalyst(V-CeO2/AC)for photocatalytic decomposition of water to hydrogen was prepared via co-impregnation method.The chemical composition,mineral phase,morphology,and optical performances of the synthesized catalyst samples were characterized by XRF,XRD,SEM,UV-Vis DRS,and so on.XRD and SEM results show that calcium silicate hydrate(Ca1.5SiO3.5·xH2O)mineral phase is formed in the carrier sample,and the prepared catalyst specimens are made up of approximately 50 nm particles.After 6 hours of xenon lamp irradiation,the catalyst supported on V-doped 8wt%CeO2 exhibits the highest photocatalytic hydrogen production activity(8292μmol/g),which is attributed to the interaction between the V-doped CeO2 active components and FeO existed in catalyst carrier.A possible photocatalytic decomposition of water for hydrogen production mechanism over the V-8CeO2/AC catalyst was proposed. 展开更多
关键词 V-doped CeO2 alkali-activated-steel-slag-based catalyst photocatalysis water splitting hydrogen production
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First-principles investigation on N/C co-doped CeO2 认领 引用
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作者 任荣康 张明举 +3 位作者 彭健 牛猛 李健宁 郑树凯 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第3期384-387,共4页
The N and C doping effects on the crystal structures, electronic and optical properties of fluorite structure CeO2 have been investigated using the first-principles calculation. Co-doping these two elements results in... The N and C doping effects on the crystal structures, electronic and optical properties of fluorite structure CeO2 have been investigated using the first-principles calculation. Co-doping these two elements results in the local lattice distortion and volume expansion of CeO2. Compared with the energy hand structure of pure CeO2, some local energy levels appear in the forbidden band, which may facilitate the light absorption. Moreover, the enhanced photo-catalytic properties of CeO2 were explained through the absorption spectra and the selection rule of the band-to-band transitions. 展开更多
关键词 first-principles N/C co-doped CeO2 photo-catalytic activity
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Preparation and photocatalytic activity of Cu2+-doped TiO2/SiO2 认领 引用 被引量：9
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作者 Ru-fen Chen Cui-xuan Zhang +1 位作者 Juan Deng Guo-qiang Song 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2009年第2期220-225,共6页
Cu^2+-doped nanostructured TiO2-coated SiO2(TiO2/SiO2)particles were prepared by the layer-by-layer assembly technique and their photocatalytic property was studied.TiO2 colloids were synthesized by the sol-gel method... Cu^2+-doped nanostructured TiO2-coated SiO2(TiO2/SiO2)particles were prepared by the layer-by-layer assembly technique and their photocatalytic property was studied.TiO2 colloids were synthesized by the sol-gel method using TiOSO4 as a precursor.The experimental results showed that TiO2 nanopowders on the surface of SiO2 particles were well distributed and compact.The amount of TiO2 increased with the increase in coating layers.The shell structure appeared to be composed of anatase titania nanocrystals at 550℃.The 2-layer coated TiO2 particles on the surface showed a higher degradation rate compared with all the different-layer samples.The photocatalytic activity of Cu^2+-doped TiO2/SiO2 was higher than that ofundoped TiO2/SiO2.The optimum dopant content was about 0.10wt%. 展开更多
关键词 nanostructured TiO2 SiO2 particles layer-byqayer assembly Cu^2+-doped photocatalytic activity
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Ultra-stable Eu3+-doped CsPbCl2Br1 perovskite quantum dots glass for optical temperature sensing 认领 引用 被引量：14
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作者 Yanxia Yu Guangzhan Shao +4 位作者 Ling Ding Huiling Zhang Xiaojuan Liang Jianping Liu Weidong Xiang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2021年第12期1497-1505,I0002,共9页
In this work,Eu3+-doped CsPbCl2Br1 in borosilicate glass was successfully synthesized by the melt quenching annealing technique and crystallization method.This work reports a novel Eu3+-doped CsPbCl2Br_... In this work,Eu3+-doped CsPbCl2Br1 in borosilicate glass was successfully synthesized by the melt quenching annealing technique and crystallization method.This work reports a novel Eu3+-doped CsPbCl2Br1 perovskite quantum dots(QDs)glass with high sensitivity for optical temperature sensing.The relation of fluorescence intensity ratio(FIR)with the temperature was studied in the temperature range of 80-440 K.Notably,the maximum absolute temperature sensitivity(Sa)and relative temperature sensitivity(Sr)of Eu3+-doped CsPbCl2Br1 perovskite QDs glass can reach as high as 0.0315 K-1 and3.097%/K,respectively.Meanwhile,Eu3+-doped CsPbCl2Br1 QDs glass demonstrates good water resistance,excellent thermal and cold cycling stability performance,The Eu3+-doped QDs glass materials can bring inspiration to the future exploration of rare earth ion-doped QDs glass material on the application of optical temperature sensing in the future. 展开更多
关键词 Eu3+-doped CsPbCl2Br1quantum dots Glass Optical temperature sensing Stability Rare earths
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Properties of Co-Doped 0.92(Na0.5Bi0.5) TiO3-0.08BaTiO3 Lead-Free Ceramics 认领 引用 被引量：4
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作者 江向平 郑严艳 +3 位作者 江福兰 刘利华 郭建荣 陈王丽华 《Chinese Physics Letters》 SCIE EI CAS 2007年第11期3257-3259,共3页
Lead-free piezoelectric ceramics 0.92（Bi0.5Na0.5）TiO3-0.08BaTiO3 ＋ xmol% Co3＋ （BNBT-Co, x = 0-8） are prepared by the solid state reaction method. Effects of the amount of Co^3＋ on the electrical properties and ... Lead-free piezoelectric ceramics 0.92（Bi0.5Na0.5）TiO3-0.08BaTiO3 ＋ xmol% Co3＋ （BNBT-Co, x = 0-8） are prepared by the solid state reaction method. Effects of the amount of Co^3＋ on the electrical properties and phase transition are studied. The results indicate that the addition of Co^3＋ enhances the mechanical quality factor Q^3＋ significantly, whereas the dissipation factor tanδ has a minimum value at x = 3.5. Meanwhile, addition of Co^3＋ leads to small decreases of piezoelectric constant d33, and planar electromechanical coupling kp. The present 0.92（Bio.aNao.5） TiO3-0.08BaTiO3＋3.5 moi% Co^3＋ ceramics exhibit good performance with mechanical quality factor Qm = 910, piezoelectric constant d33 = 106pC/N, planar electromechanical coupling kp =10% and dissipation factor tanδ = 1.1% at 1 kHz. Saturated polarization hysteresis loops have been obtained for BNBT-Co ceramics. Two dielectric peaks at depolarization temperature Td and Tm appear in the curves of ε33^T vs temperature for the pure BNBT ceramics. However, the first dielectric peak Td disappears after the addition of Co^3＋, which means that the transition from ferroelectric to antiferroelectric phase has been eliminated. 展开更多
关键词 coated conductor buffer layer self-epitaxy CeO2
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Emission property of Y2O3-doped Mo secondary emitter 认领 引用 被引量：2
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作者 WANG Jin-shu LIU Wei +3 位作者 LI Hong-yi GAO Fei REN Zhi-yuan ZHOU Mei-ling 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS 2010年第2期233-237,共5页
Y2O3-doped Mo secondary emitters were prepared by liquid-liquid doping and solid-solid doping,respectively.The back-scattered scanning observation result indicates that the emitter prepared by liquid-liquid doping has... Y2O3-doped Mo secondary emitters were prepared by liquid-liquid doping and solid-solid doping,respectively.The back-scattered scanning observation result indicates that the emitter prepared by liquid-liquid doping has fine microstructure whereas that prepared by solid-solid doping has large grain size.Y2O3-doped Mo emitter with small grain size prepared by liquid-liquid doping exhibits high emission property,i.e.,the secondary electron yield can get to 5.24,about 1.7 times that prepared by solid-solid doping.Moreover,Y2O3-doped Mo emitter exhibits the best emission performance among La2O3-doped Mo,Y2O3-doped Mo,Gd2O3-doped Mo and Ce2O3-doped Mo emitters due to the largest penetration depth of primary electrons and escape depth of secondary electrons in this emitter.The secondary emission of the emitter with small grain size can be explained by reflection emission model and transmission emission model,whereas only transmission emission exists in the emitter with large grain size. 展开更多
关键词 Y2O3-doped Mo powder metallurgy emission property microstructure
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Dielectric and Ferroelectric Properties of La-Doped SrBi2Nb2O9 Ceramics 认领 引用 被引量：2
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作者 刘国珍 顾豪爽 +2 位作者 汪春昌 仇杰 吕惠宾 《Chinese Physics Letters》 SCIE EI CAS 2007年第8期2387-2389,共3页
Sr1-xLa2x/3Bi2Nb20O （0 ≤ x ≤0.2） ceramic samples are prepared by the solid-state reaction method. Their structure, dielectric and ferroelectric properties are investigated. The incorporation of La^3＋ improves the... Sr1-xLa2x/3Bi2Nb20O （0 ≤ x ≤0.2） ceramic samples are prepared by the solid-state reaction method. Their structure, dielectric and ferroelectric properties are investigated. The incorporation of La^3＋ improves the den- sification and decreases the grain size of the ceramics without changing the crystal structure. The remanent polarization 2PT increases with increasing La content and reaches a maximum value of 22.8μC/cm^2 at x = 0.125, which is approximately 60% larger than that of pure SrBi2Nb2O9. The Curie temperature keeps almost unchanged at a value of about 440℃. The relationship between doping and the ferroeleetrie and dielectric properties are discussed. 展开更多
关键词 coated conductor buffer layer self-epitaxy CeO2
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Humidity sensing properties of La3+ and K^+ co-doped Ti0.9Sn0.1O_2 thin films 认领 引用 被引量：2
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作者 Mansoor Anbia S.E Moosavi Fard 《Journal of Rare Earths》 SCIE EI CAS CSCD 2011年第7期668-672,共5页
The humidity sensing properties of La^3＋ and K^＋ co-doped Ti0.9Sn0.1O2 thin films were investigated. The humidity sensitive thin films were prepared by sol-gel method on alumina substrates. The sensing behaviors of ... The humidity sensing properties of La^3＋ and K^＋ co-doped Ti0.9Sn0.1O2 thin films were investigated. The humidity sensitive thin films were prepared by sol-gel method on alumina substrates. The sensing behaviors of thin films were inspected at different sintering temperatures by constructing a humidity-impedance measuring system. It was found that the addition of rare earth ion La^3＋ and alkali ion K^＋ was beneficial for improving the humidity sensitive properties of the samples and La0.003K0.5Ti0.9Sn0.1O2 sintered at 500 ℃ for 4 h showed the best humidity sensing properties. The impedance of this thin film decreased from 109 to 104 Ω with excellent linearity in the humidity range of 11%-95%. Narrow hysteresis loop, prominent stability and high sensitivity were obtained. The effects of dopant con-tent and doping mechanism on humidity sensitivity were also discussed in terms of segregation of rare earth ions at grain boundaries and granularity of crystalline and influence of K^＋ on the decrease in the intrinsic resistance of the materials, and increase in the number of wa-ter adsorption sites. 展开更多
关键词 humidity sensing thin film rare earths La^3＋-doped K^＋-doped Ti0.9Sn0.1O2
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Three-photon-excited fluorescence of Tb3+-doped CaO-Al_2O_3-SiO_2 glass by femtosecond laser irradiation 认领 引用 被引量：3
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作者 马红萍 祝邦文 邹凤楼 《Journal of Rare Earths》 SCIE EI CAS 2008年第6期928-931,共4页
A near infrared to visible blue, green, and red upconversion luminescence in a Tb^3＋-doped CaO-Al2O3-SiO2 glass was studied, which was excited using 800 nm femtosecond laser irradiation. The upconversion luminescence... A near infrared to visible blue, green, and red upconversion luminescence in a Tb^3＋-doped CaO-Al2O3-SiO2 glass was studied, which was excited using 800 nm femtosecond laser irradiation. The upconversion luminescence was attributed to ^5D3→^7F5, ^5D3→^7F4, ^5D3→^7F3, ^5D4→^7F6, ^5D4→^7F5, ^5D4→^7F4, and ^5D4→^7F3 transitions of Tb^3＋. The relationship between upconversion luminescence intensity and the pump power indicated that a three-photon simultaneous absorption process was dominant in this upconversion luminescence. The intense red, green, and blue upconversion luminescence of Tb^3＋-doped CaO-Al2O3-SiO2 glass may be potentially useful in developing three-dimensional display applications. 展开更多
关键词 three-photon-excited fluorescence three-dimensional （3D） volumetric display Tb^3＋-doped CaO-Al2O3-SiO2 glass rare earths
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Novel Electro-Optical Modulator Utilizing GeO_2-Doped Silica Waveguide 认领 引用 被引量：2
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作者 李九生 贾大功 《Transactions of Tianjin University》 EI CAS 2009年第3期222-224,共3页
In order to achieve a modulator with broad bandwidth and perfect impedance match,a novel electro-optical modulator based on GeO2-doped silica waveguides on silicon substrate is designed.The finite element model of the... In order to achieve a modulator with broad bandwidth and perfect impedance match,a novel electro-optical modulator based on GeO2-doped silica waveguides on silicon substrate is designed.The finite element model of the whole electro-optical modulator is established by means of ANSYS.With the finite element method analysis,the performance of the novel modulator is predicted.The simulation reveals that the designed modulator operates with a product of 3 dB optical bandwidth and modulating length of 226.59 GHz·cm,and a characteristic impedance of 51.6 Ω at 1 550 nm wavelength.Moreover,the calculated electrical reflected power of coplanar waveguide electrode is below-20 dB in the frequency ranging from 45 MHz to 65 GHz.Therefore,the designed modulator has wide modulation bandwidth and perfect impedance match. 展开更多
关键词 optical modulator GeO2-doped silica finite element method
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Effects of annealing temperature and neodymium concentration on structural and photoluminescence properties of Nd3+-doped Y2O3-SiO2 powders 认领 引用 被引量：3
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作者 NoSoung Myoung Gyeong Bok Jung 《Journal of Rare Earths》 SCIE EI CAS CSCD 2021年第6期651-656,I0002,共6页
We report the structural and photoluminescence(PL) properties of Nd3+-doped Y2O3-SiO2 powders(Y2O3-SiO2:Nd3+) as functions of annealing temperature and Nd3+ ion doping concentration.Y2O_(... We report the structural and photoluminescence(PL) properties of Nd3+-doped Y2O3-SiO2 powders(Y2O3-SiO2:Nd3+) as functions of annealing temperature and Nd3+ ion doping concentration.Y2O3-SiO2:Nd3+powders were prepared using the high-energy ball-milling(HEBM) method,and their structural and PL properties were investigated using X-ray diffraction(XRD),Fourier transform infrared(FTIR) spectroscopy,and PL spectroscopy.The XRD results reveal a cubic phase without impurities,and the peak broadening decreases with an increase in annealing temperature due to the increase in the crystallite size.The PL emission intensity increases with an increase in annealing temperature.The highest PL emission intensity is observed for the 300-min milled mixture annealed at 1000℃ for 1 h with a Nd3+ concentration of 1 mol%.The PL peaks excited by 800 nm radiation were detected,centered at 1080 nm(4F3/2→4I11/2) and 1350 nm(4F3/2→4I13/2). 展开更多
关键词 Nd3+-doped Y2O3-SiO2powders High-energy ball-milling method Near infrared photoluminescence emission Rare earth Annealing temperature
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