As the fourth-generation light source,solid-state lighting has developed rapidly in the past 30 years due to its advantages of high efficiency and environmental protection.It is widely used in various scenes such as a...As the fourth-generation light source,solid-state lighting has developed rapidly in the past 30 years due to its advantages of high efficiency and environmental protection.It is widely used in various scenes such as automobile headlights,projection displays,industrial production,and remote lighting.High-power,high-brightness white light-emitting diodes(LEDs)and laser diodes(LDs)technology put forward new requirements for the service stability of color conversion materials.Garnet phosphor ceramics have emerged with their unique advantages of withstanding high power excitation density and the flexibly tunable spectrum.In this article,the research progress of garnet based phosphor ceramics for high-power solid-state lighting was comprehensively reviewed.Firstly,the band gap and coordination environment regulations of luminescence centers of garnet phosphor were summarized.Secondly,the improvement of luminous efficacy via defects regulation was discussed.Thirdly,the relationship between the geometric design and the lighting performance was elucidated.Fourthly,the characterization methods of phosphor ceramics for laser lighting were introduced and illustrated.Finally,the development trend of garnet phosphor ceramics in solid state lighting and display was prospected.展开更多
Y_(3)Fe_(5)O_(12)(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality s...Y_(3)Fe_(5)O_(12)(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality single crystals.Dy^(3+)doping is expected to improve the optical and magneto-optical prope rties.However,high quality Dy:YIG crystals and the adjustment of Dy^(3+)on the structure and optical behavior of YIG crystal remain unclear,impeding its practical applications.Herein,a series of Y_(3-x)Dy_(x)Fe_(5)O_(12)(x=0,0.5,1.0,1.5,3)solid solution crystals was grown by the flux-Bridgman method and single crystals up to 25 mm were obtained.With the introduction of Dy^(3+),lattice parameters are gradually enlarged from 1.2379 nm(YIG)to 1.2420 nm(DyIG).Typical Dy^(3+)absorption peaks are observed around 1070,1265 and 1670 nm.The refractive index decreases from 2.37(500 nm)to 2.10(2500 nm)for YIG crystal,and it reduces from 2.47(500 nm)to 2.16(2500 nm)for DyIG crystal.The optical bandgaps remain almost unchanged for Dy:YIG crystals.The optical dispersion of the refractive indices was finely fitted by the Wemple and DiDomenico(WDD)and the Sellmeier models,respectively.With the increase of Dy^(3+)content,the saturation magnetization(Ms)decreases significantly from 23.62 emu/g(YIG)to 5.33 emu/g(DyIG).Small coercive field is persisted for this system,endowing small external magnetic field.These results provide valuable references for the manipulation of rare earths on the properties of magnetooptical crystals,which is beneficial to the design of high-performance garnet crystals for the application of optical switching and non-reciprocal related devices.展开更多
Rare earth garnet(R_(3)Fe_(5)O_(12),RIG)single crystals are the most ideal magneto-optical medium for optical isolators for wavelength longer than 1.1μm,which has been commercially used in optical fiber communication...Rare earth garnet(R_(3)Fe_(5)O_(12),RIG)single crystals are the most ideal magneto-optical medium for optical isolators for wavelength longer than 1.1μm,which has been commercially used in optical fiber communications.However,it is still a great challenge to grow large size RIG single crystals.In this work,highquality Y3 Fe5 O12(YIG)and Bi_(0.9)Tb_(2.1)Fe_(5)O_(12)(Bi:TIG)single crystals were successfully grown by the flux-Bridgman method for the first time.The as-grown crystals up to 20 mm in diameter was obtained using the PbO-B_(2)O_(3)flux.The transmittance of YIG crystals is over 75%in the region of 1100-2500 nm.TIG crystals also have good transmittance in the range of 1100-1700 nm,and show typical Tb absorption from 1700 to 2500 nm.The specific Faraday rotations of YIG and Bi_(0.9)Tb_(2.1)Fe_(5)O_(12) crystals are 185(°)/cm and-1250(°)/cm at 1550 nm,which are comparable to the commercial RIG crystals grown by LPE method.The present results indicate that flux-Bridgman method shows great potential to grow large size and high-quality RIG magneto-optical crystals.展开更多
All-solid-state batteries have attracted much attention due to their improved safety and higher energy density as compared to the conventional batteries.Owing to the excellent chemical stability against lithium metal ...All-solid-state batteries have attracted much attention due to their improved safety and higher energy density as compared to the conventional batteries.Owing to the excellent chemical stability against lithium metal and relatively high ionic conductivity at room-temperature,garnet-type fast lithium ion conductors with three-dimensional lithium ion transport channels are promising solid electrolytes for all-solid-state batteries.In order to better understand the intrinsic lithium-ion transport mechanisms and prevent lithium dendrite formation,it is desired to investigate single-crystal solid electrolytes.In this perspective,we review several methods reported to grow single crystals of garnet-type electrolytes.Pros and cons of different growth methods are discussed.Furthermore,we introduce some case studies on electrochemical properties of garnet-type single crystals.In addition,we provide some perspectives about potential research directions of single-crystal solid electrolytes for all-solid-state batteries.展开更多
This paper theoretically investigates the effects of crystal field and exchange interaction field on magnetic properties in dysprosium gallium garnet under extreme conditions （low temperatures and high magnetic field...This paper theoretically investigates the effects of crystal field and exchange interaction field on magnetic properties in dysprosium gallium garnet under extreme conditions （low temperatures and high magnetic fields） based on quantum theory. Here, five sets of crystal field parameters are discussed and compared. It demonstrates that, only considering the crystal field effect, the experiments can not be successfully explained. Thus, referring to the molecular field theory, an effective exchange field associated with the Dy-Dy exchange interaction is further taken into account. Under special consideration of crystal field and the exchange interaction field, it obtains an excellent agreement between the theoretical results and experiments, and further confirms that the exchange interaction field between rare-earth ions has great importance to magnetic properties in paramagnetic rare-earth gallium garnets.展开更多
Compensated ferrimagnetic insulators are particularly interesting for enabling functional spintronic,optical,and microwave devices.Among many different garnets,Gd_(3)Fe_(5)O_(12)(GdIG)is a representative compensated f...Compensated ferrimagnetic insulators are particularly interesting for enabling functional spintronic,optical,and microwave devices.Among many different garnets,Gd_(3)Fe_(5)O_(12)(GdIG)is a representative compensated ferrimagnetic insulator.In this paper,we will study the evolution of the surface morphology,the magnetic properties,and the magnetization compensation through changing the following parameters:the annealing temperature,the growth temperature,the annealing duration,and the choice of different single crystalline garnet substrates.Our objective is to find the optimized growth condition of the GdIG films,for the purpose of achieving a strong perpendicular magnetic anisotropy(PMA)and a flat surface,together with a small effective damping parameter.Through our experiments,we have found that the surface roughness approaching 0.15 nm can be obtained by choosing the growth temperature around 700℃,together with an enhanced PMA.We have also found the modulation of magnetic anisotropy by choosing different single crystalline garnet substrates which change the tensile strain to the compressive strain.A measure of the effective magnetic damping parameter(α_(eff)=0.04±0.01)through a spin pumping experiment in a GdIG/Pt bilayer is also made.Through optimizing the growth dynamics of GdIG films,our results could be useful for synthesizing garnet films with a PMA,which could be beneficial for the future development of ferrimagnetic spintronics.展开更多
基金This work was financially supported from the National Key Re-search and Development Program of China(No.2021YFB3501700)the National Natural Science Foundation of China(Nos.52202135,61975070,51902143 and 61971207)+7 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Key Research and Development Project of Jiangsu Province(Nos.BE2021040 and BE2019033)the Natural Science Foundation of Jiangsu Province(Nos.BK20191467 and BK20221226)the Postgrad-uate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_2568)the International S&T Cooperation Program of Jiangsu Province(Nos.BZ2019063,BZ2020045 and BZ2020030)the Natural Science Foundation of the Jiangsu Higher Education In-stitutes of China(Nos.19KJB430018 and 20KJA430003)the Special Project for Technology Innovation of Xuzhou City(Nos.KC19250,KC20201,KC20244 and KC21379)Open Project of State Key Laboratory of Advanced Materials and Electronic Components(No.FHR-JS-202011017).The authors would like to show great appreci-ation to Prof.Ole Bjarlin Jensen from the Technical University of Denmark for his long-term support and guidance on diode laser-related knowledge and technique.
文摘As the fourth-generation light source,solid-state lighting has developed rapidly in the past 30 years due to its advantages of high efficiency and environmental protection.It is widely used in various scenes such as automobile headlights,projection displays,industrial production,and remote lighting.High-power,high-brightness white light-emitting diodes(LEDs)and laser diodes(LDs)technology put forward new requirements for the service stability of color conversion materials.Garnet phosphor ceramics have emerged with their unique advantages of withstanding high power excitation density and the flexibly tunable spectrum.In this article,the research progress of garnet based phosphor ceramics for high-power solid-state lighting was comprehensively reviewed.Firstly,the band gap and coordination environment regulations of luminescence centers of garnet phosphor were summarized.Secondly,the improvement of luminous efficacy via defects regulation was discussed.Thirdly,the relationship between the geometric design and the lighting performance was elucidated.Fourthly,the characterization methods of phosphor ceramics for laser lighting were introduced and illustrated.Finally,the development trend of garnet phosphor ceramics in solid state lighting and display was prospected.
基金Project supported by Joint Fund NSAF of National Natural Science Foundation of ChinaChina Academy ofEngineering Physics(U2130124)+1 种基金Shanghai Municipal Commission of Economy and Informatization,China(GYQJ-2020-1-19)theNational Natural Science Foundation of China(52172121)。
文摘Y_(3)Fe_(5)O_(12)(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality single crystals.Dy^(3+)doping is expected to improve the optical and magneto-optical prope rties.However,high quality Dy:YIG crystals and the adjustment of Dy^(3+)on the structure and optical behavior of YIG crystal remain unclear,impeding its practical applications.Herein,a series of Y_(3-x)Dy_(x)Fe_(5)O_(12)(x=0,0.5,1.0,1.5,3)solid solution crystals was grown by the flux-Bridgman method and single crystals up to 25 mm were obtained.With the introduction of Dy^(3+),lattice parameters are gradually enlarged from 1.2379 nm(YIG)to 1.2420 nm(DyIG).Typical Dy^(3+)absorption peaks are observed around 1070,1265 and 1670 nm.The refractive index decreases from 2.37(500 nm)to 2.10(2500 nm)for YIG crystal,and it reduces from 2.47(500 nm)to 2.16(2500 nm)for DyIG crystal.The optical bandgaps remain almost unchanged for Dy:YIG crystals.The optical dispersion of the refractive indices was finely fitted by the Wemple and DiDomenico(WDD)and the Sellmeier models,respectively.With the increase of Dy^(3+)content,the saturation magnetization(Ms)decreases significantly from 23.62 emu/g(YIG)to 5.33 emu/g(DyIG).Small coercive field is persisted for this system,endowing small external magnetic field.These results provide valuable references for the manipulation of rare earths on the properties of magnetooptical crystals,which is beneficial to the design of high-performance garnet crystals for the application of optical switching and non-reciprocal related devices.
基金Project supported by State Key Laboratory of Crystal Materials,China(KF1810)Shanghai Municipal Commission of Economy and Informatization,China(GYQJ-2020-1-19)。
文摘Rare earth garnet(R_(3)Fe_(5)O_(12),RIG)single crystals are the most ideal magneto-optical medium for optical isolators for wavelength longer than 1.1μm,which has been commercially used in optical fiber communications.However,it is still a great challenge to grow large size RIG single crystals.In this work,highquality Y3 Fe5 O12(YIG)and Bi_(0.9)Tb_(2.1)Fe_(5)O_(12)(Bi:TIG)single crystals were successfully grown by the flux-Bridgman method for the first time.The as-grown crystals up to 20 mm in diameter was obtained using the PbO-B_(2)O_(3)flux.The transmittance of YIG crystals is over 75%in the region of 1100-2500 nm.TIG crystals also have good transmittance in the range of 1100-1700 nm,and show typical Tb absorption from 1700 to 2500 nm.The specific Faraday rotations of YIG and Bi_(0.9)Tb_(2.1)Fe_(5)O_(12) crystals are 185(°)/cm and-1250(°)/cm at 1550 nm,which are comparable to the commercial RIG crystals grown by LPE method.The present results indicate that flux-Bridgman method shows great potential to grow large size and high-quality RIG magneto-optical crystals.
基金This work was supported by the start-up funds from the University of California,Riverside.The authors thank Dr.Yutao Li from the University of Texas at Austin for helpful discussion.
文摘All-solid-state batteries have attracted much attention due to their improved safety and higher energy density as compared to the conventional batteries.Owing to the excellent chemical stability against lithium metal and relatively high ionic conductivity at room-temperature,garnet-type fast lithium ion conductors with three-dimensional lithium ion transport channels are promising solid electrolytes for all-solid-state batteries.In order to better understand the intrinsic lithium-ion transport mechanisms and prevent lithium dendrite formation,it is desired to investigate single-crystal solid electrolytes.In this perspective,we review several methods reported to grow single crystals of garnet-type electrolytes.Pros and cons of different growth methods are discussed.Furthermore,we introduce some case studies on electrochemical properties of garnet-type single crystals.In addition,we provide some perspectives about potential research directions of single-crystal solid electrolytes for all-solid-state batteries.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11004005 and 60971019)the Young Scholars Fund of Beijing University of Chemical Technology,China(Grant No.QN0724)
文摘This paper theoretically investigates the effects of crystal field and exchange interaction field on magnetic properties in dysprosium gallium garnet under extreme conditions （low temperatures and high magnetic fields） based on quantum theory. Here, five sets of crystal field parameters are discussed and compared. It demonstrates that, only considering the crystal field effect, the experiments can not be successfully explained. Thus, referring to the molecular field theory, an effective exchange field associated with the Dy-Dy exchange interaction is further taken into account. Under special consideration of crystal field and the exchange interaction field, it obtains an excellent agreement between the theoretical results and experiments, and further confirms that the exchange interaction field between rare-earth ions has great importance to magnetic properties in paramagnetic rare-earth gallium garnets.
基金Project supported by the National Key R&D Program of China(Grant Nos.2017YFA0206200 and 2016YFA0302300)the Basic Science Center Project of the National Natural Science Foundation of China(Grant No.51788104)+2 种基金the National Natural Science Foundation of China(Grant Nos.11774194,11804182,51831005,and 11811082)Beijing Natural Science Foundation(Grant No.Z190009)the Beijing Advanced Innovation Center for Future Chip(ICFC).
文摘Compensated ferrimagnetic insulators are particularly interesting for enabling functional spintronic,optical,and microwave devices.Among many different garnets,Gd_(3)Fe_(5)O_(12)(GdIG)is a representative compensated ferrimagnetic insulator.In this paper,we will study the evolution of the surface morphology,the magnetic properties,and the magnetization compensation through changing the following parameters:the annealing temperature,the growth temperature,the annealing duration,and the choice of different single crystalline garnet substrates.Our objective is to find the optimized growth condition of the GdIG films,for the purpose of achieving a strong perpendicular magnetic anisotropy(PMA)and a flat surface,together with a small effective damping parameter.Through our experiments,we have found that the surface roughness approaching 0.15 nm can be obtained by choosing the growth temperature around 700℃,together with an enhanced PMA.We have also found the modulation of magnetic anisotropy by choosing different single crystalline garnet substrates which change the tensile strain to the compressive strain.A measure of the effective magnetic damping parameter(α_(eff)=0.04±0.01)through a spin pumping experiment in a GdIG/Pt bilayer is also made.Through optimizing the growth dynamics of GdIG films,our results could be useful for synthesizing garnet films with a PMA,which could be beneficial for the future development of ferrimagnetic spintronics.
