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Mn^(2+)掺杂对YAG∶Ce^(3+)荧光陶瓷发光性能的影响
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作者 喻彬 孙炳恒 +7 位作者 付秀梅 周世斌 郝好莹 沈方樑 范金太 姜本学 张龙 孙军 《发光学报》 EI CAS CSCD 北大核心 2024年第5期762-771,共10页
过渡族金属Mn^(2+)掺杂的石榴石荧光陶瓷被认为是实现高显色激光照明的候选材料。然而,由于Mn^(2+)在不同配位环境下离子半径的多样性,Mn^(2+)掺杂石榴石陶瓷体系设计方案尚不明确。本文采用真空烧结技术制备得到不同浓度Mn^(2+)掺杂的... 过渡族金属Mn^(2+)掺杂的石榴石荧光陶瓷被认为是实现高显色激光照明的候选材料。然而,由于Mn^(2+)在不同配位环境下离子半径的多样性,Mn^(2+)掺杂石榴石陶瓷体系设计方案尚不明确。本文采用真空烧结技术制备得到不同浓度Mn^(2+)掺杂的YAG∶Ce^(3+)荧光陶瓷,并将Mn^(2+)分别设计进入八面体(OC)和十二面体(DO)格位。通过表征样品物相和显微结构、光致发光、荧光寿命、量子效率等,并通过LD激光器激发对荧光陶瓷的发光性能进行研究。实验结果表明,在添加电荷与体积补偿剂SiO_(2)的前提下,相比Mn^(2+)进入十二面体格位,Mn^(2+)进入八面体后石榴石的晶体结构更加稳定。因此,当Mn^(2+)的浓度控制在0.5%^(6)%(at)范围内,OC系列样品的量子效率高于DO系列样品。此外,OC系列样品的PL谱中位于588 nm和725 nm处的发射峰分别对应于Mn^(2+)占据八面体和十二面体格位的^(4)T_(1)→^(6)A_(1)电子跃迁,而DO系列样品中位于572 nm处的发射峰则源于Mn^(2+)占据扭曲的十二面体格位产生的电子跃迁。得益于Ce^(3+)→Mn^(2+)间高效的能量传递,将浓度为6%(at)的Mn^(2+)设计进入YAG∶Ce^(3+)中八面体格位制得荧光陶瓷,封装得到的激光白光光源的显色指数为70.8,相对色温为5117 K。本文对于Mn^(2+)掺杂的石榴石发光材料的开发研究是有力补充,也为提升YAG∶Ce^(3+)荧光陶瓷光谱中的红光成分,进而提高医疗、显示等领域的激光光源的显色性能提供借鉴。 展开更多
关键词 荧光陶瓷 Ce^(3+)掺杂 Mn^(2+)掺杂 格位
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Ce^(3+)-Tb^(3+)共掺杂黄磷炉渣微晶玻璃的发光与能量传递
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作者 吴玮强 李文斌 +3 位作者 黄小凤 龙雨欣 邓凯沣 王宇 《功能材料》 CAS CSCD 北大核心 2024年第1期1103-1110,共8页
以黄磷炉渣为原料,采用高温熔融法制备Ce^(3+)-Tb^(3+)共掺杂黄磷炉渣发光微晶玻璃,通过差热分析(DTA)、X射线衍射(XRD)、稳态/瞬态荧光(FLS)、CIE色度等探究不同的Tb^(3+)掺杂量对微晶玻璃析出晶相、发光性能和样品色度的影响。结果表... 以黄磷炉渣为原料,采用高温熔融法制备Ce^(3+)-Tb^(3+)共掺杂黄磷炉渣发光微晶玻璃,通过差热分析(DTA)、X射线衍射(XRD)、稳态/瞬态荧光(FLS)、CIE色度等探究不同的Tb^(3+)掺杂量对微晶玻璃析出晶相、发光性能和样品色度的影响。结果表明,Ce^(3+)和Tb^(3+)的引入,微晶玻璃主晶相为硅灰石,在310 nm波长激发下,随着Tb^(3+)掺杂量增加,位于380 nm处Ce^(3+)的特征发射峰减小,543 nm处Tb^(3+)的特征发射峰增强,证实Ce^(3+)和Tb^(3+)之间存在能量传递,能量传递效率达到24.55%。此外,通过调整Tb^(3+)掺杂量,微晶玻璃发光颜色可由蓝光调至绿光,从而实现发光颜色的可控化。 展开更多
关键词 黄磷炉渣 发光 Ce^(3+) Tb^(3+) 能量传递
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溶液燃烧法制备Ce^(3+)掺杂LaAlO_(3)粉体及其荧光性能研究
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作者 邰越 许凌子 +2 位作者 吴静 孟竺 储刚 《稀有金属与硬质合金》 CAS CSCD 北大核心 2024年第3期29-33,39,共6页
以La(NO_(3))_(3)·6H_(2)O、Al(NO_(3))_(3)·9H_(2)O、Ce(NO_(3))_(3)·6H_(2)O为原料,C_(2)H_(5)NO_(2)为还原剂,采用溶液燃烧法合成La_(1-x)Ce_(x)AlO_(3)(x=0.01,0.02,0.03,0.04,0.05)样品。采用XRD、SEM、UV-Vis DRS... 以La(NO_(3))_(3)·6H_(2)O、Al(NO_(3))_(3)·9H_(2)O、Ce(NO_(3))_(3)·6H_(2)O为原料,C_(2)H_(5)NO_(2)为还原剂,采用溶液燃烧法合成La_(1-x)Ce_(x)AlO_(3)(x=0.01,0.02,0.03,0.04,0.05)样品。采用XRD、SEM、UV-Vis DRS、XPS和XRF对实验样品进行分析。结果表明,在825℃下保温4 h制备的La_(0.97)Ce_(0.03)AlO_(3)相比其他温度或Ce掺杂量的LaAlO_(3)而言,XRD特征峰更加突出和明显,其颗粒分散,轮廓清晰,晶粒尺寸为21.59 nm;其在紫外-可见光区域吸收变强,带隙宽度为4.86 eV。Ce^(3+)进入LaAlO_(3)晶格中占据了部分La^(3+)的位置,Ce^(3+)最佳掺杂浓度为0.03,其发射光谱的最强特征峰出现在525 nm处,发黄绿色光。 展开更多
关键词 溶液燃烧法 LaAlO_(3) Ce^(3+) 掺杂 荧光
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Lu^(3+)掺杂Na_(5)Y_(9)F_(32)∶Ho^(3+)/Yb^(3+)/Ce^(3+)单晶体的增强红色上转换发光与光学温度传感性能
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作者 徐义松 方立志 +2 位作者 夏海平 周雄 宋宏伟 《发光学报》 EI CAS CSCD 北大核心 2024年第7期1104-1113,共10页
采用密封的坩埚下降法技术生长了一系列Lu^(3+)(摩尔分数0、0.6%、1.2%、1.8%)掺杂Na_(5)Y_(9)F_(32)∶Ho^(3+)/Yb^(3+)/Ce^(3+)单晶体。在980 nm LD激发下,观察到单晶体的绿光543 nm(^(5)S_(2)/^(5)F_(4)→^(5)I_(8))、红光656 nm(^(5)... 采用密封的坩埚下降法技术生长了一系列Lu^(3+)(摩尔分数0、0.6%、1.2%、1.8%)掺杂Na_(5)Y_(9)F_(32)∶Ho^(3+)/Yb^(3+)/Ce^(3+)单晶体。在980 nm LD激发下,观察到单晶体的绿光543 nm(^(5)S_(2)/^(5)F_(4)→^(5)I_(8))、红光656 nm(^(5)F_(5)→^(5)I_(8))以及近红外750 nm(^(5)S_(2)/^(5)F4→^(5)I_(7))上转换发光。从上转换发光强度随激发光强度的变化情况,确定了543 nm、656 nm与750 nm的发光为双光子跃迁过程。研究了Lu^(3+)离子掺杂浓度对其发光强度与荧光寿命的影响情况,随着Lu^(3+)掺杂浓度从0增加到1.8%,单晶体中的656 nm红光逐步增强,543 nm绿光与750 nm近红外光随之减弱,红绿光强度比从0.01增加到了1.55,而543 nm荧光寿命从1.29 ms降低至0.99 ms。Lu^(3+)离子的掺入取代Y^(3+)晶格位,改变了单晶体的局域场环境,导致上转换发光强度的变化。基于随温度变化的上转换红光656 nm(^(5)F5→^(5)I8)与绿光543 nm(^(5)S_(2)/^(5)F4→^(5)I8)的发光强度变化,研究了1.8%Lu^(3+)掺杂Na_(5)Y_(9)F_(32)∶Ho^(3+)/Yb^(3+)/Ce^(3+)单晶体在298~448 K范围内的绝对灵敏度和相对灵敏度最大值分别为0.242%·K^(-1)和0.217%·K^(-1)。 展开更多
关键词 Na_(5)Y_(9)F_(32)单晶 增强上转换红光 Ho^(3+)/Yb^(3+)/Ce^(3+) 光学温度传感 能量转移
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NaYSiO_(4)∶Ce^(3+)蓝色荧光粉的发光性质及其在白光发光二极管上的应用
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作者 陈蕾 杨星宇 +2 位作者 张瀚月 宋芳 冷稚华 《发光学报》 EI CAS CSCD 北大核心 2024年第5期745-752,共8页
采用高温固相法合成了NaYSiO_(4)∶xCe^(3+)(0.01≤x≤0.05)系列蓝色荧光粉。NaYSiO_(4)∶xCe^(3+)荧光粉在250~360 nm之间的宽带吸收能与紫外LED芯片很好地匹配。NaYSiO_(4)∶xCe^(3+)荧光粉中存在多个Ce^(3+)离子荧光中心,且在紫外光... 采用高温固相法合成了NaYSiO_(4)∶xCe^(3+)(0.01≤x≤0.05)系列蓝色荧光粉。NaYSiO_(4)∶xCe^(3+)荧光粉在250~360 nm之间的宽带吸收能与紫外LED芯片很好地匹配。NaYSiO_(4)∶xCe^(3+)荧光粉中存在多个Ce^(3+)离子荧光中心,且在紫外光激发下表现出峰值波长位于414 nm附近的宽带蓝光发射。NaYSiO_(4)∶0.02Ce^(3+)荧光粉在300~350 nm紫外光激发下量子效率在25%以上。NaYSiO_(4)∶0.02Ce^(3+)荧光粉表现出优良的化学稳定性,在水中浸泡14 d后荧光强度和量子效率几乎不变。将NaYSiO_(4)∶0.02Ce^(3+)蓝色荧光粉、商用(Sr,Ba)_2SiO_(4)∶Eu^(2+)绿色荧光粉和商用(Ca,Sr)AlSiN_(3)∶Eu^(2+)红色荧光粉涂覆于310 nm紫外LED芯片上制备得到了显色指数高达95的LED器件。当驱动电流从50 mA逐渐增大到300 mA时,制备的LED器件表现出稳定的暖白光发射,其色坐标几乎不变。上述结果说明,本研究报道的NaYSiO_(4)∶0.02Ce^(3+)蓝色荧光粉在紫外LED芯片驱动的白光发光二极管照明上有着潜在应用价值。 展开更多
关键词 NaYSiO_(4):Ce^(3+) 高温固相 蓝色荧光粉 白光发光二极管 高显色指数
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无压烧结制备Y_(2)MgAl_(4)SiO_(12)∶Ce^(3+)荧光陶瓷及光学性能
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作者 王靖涛 王茗 +3 位作者 王森宇 徐祖盛 梁莹盈 张瑞 《发光学报》 EI CAS CSCD 北大核心 2024年第3期434-442,共9页
Y_(3)Al_(5)O_(12)∶Ce^(3+)荧光粉是目前白光LED的主要发光材料,但在使用时存在封装树脂因散热不佳而发生老化等问题。本文采用无压烧结制备了Y_(2)MgAl_(4)SiO_(12)∶Ce^(3+)透明陶瓷荧光体,用于替代荧光粉体和调控发光性能。首先通... Y_(3)Al_(5)O_(12)∶Ce^(3+)荧光粉是目前白光LED的主要发光材料,但在使用时存在封装树脂因散热不佳而发生老化等问题。本文采用无压烧结制备了Y_(2)MgAl_(4)SiO_(12)∶Ce^(3+)透明陶瓷荧光体,用于替代荧光粉体和调控发光性能。首先通过化学共沉淀法制备前驱体粉体,经高温煅烧后采用冷等静压成型,最后在马弗炉中1 600℃煅烧制得透明荧光陶瓷。研究了Ce^(3+)掺杂浓度和样品厚度对材料性能的影响,其中掺杂量为0.5%的样品在800 nm处具有56%的透过率,在450 K下发光强度仍能保持室温强度的84%。与蓝光芯片组装成器件测试表明,荧光陶瓷在蓝光LEDs/LDs的激发下发出白光,其CIE色度坐标分别为(0.307 6,0.332 9)和(0.308 0,0.331 6),光效分别为62.6 lm/W和146.3 lm/W。研究结果表明,YMAS∶Ce荧光陶瓷可应用于白光LEDs/LDs领域。 展开更多
关键词 无压烧结 Y_(2)MgAl_(4)SiO_(12)∶Ce^(3+) 荧光陶瓷 白光LEDs/LDs
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Gd^(3+)/Ce^(3+)对Tb^(3+)掺杂氟氧化物玻璃发光敏化作用的影响
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作者 刘瑞旺 王宏杰 +3 位作者 符博 贾亚男 周建欣 魏晋 《硅酸盐通报》 CAS 北大核心 2024年第4期1335-1340,共6页
本文采用高温熔融法制备了Gd/Tb、Gd/Ce、Gd/Ce/Tb掺杂的SiO_(2)-B_(2)O_(3)-BaF_(2)组分氟氧化物玻璃,通过测试X射线衍射光谱确定了其物相,通过测试其不同波段激发下的荧光光谱研究了不同Gd_(2)O_(3)掺量下Tb^(3+)的发光性能,并确定了G... 本文采用高温熔融法制备了Gd/Tb、Gd/Ce、Gd/Ce/Tb掺杂的SiO_(2)-B_(2)O_(3)-BaF_(2)组分氟氧化物玻璃,通过测试X射线衍射光谱确定了其物相,通过测试其不同波段激发下的荧光光谱研究了不同Gd_(2)O_(3)掺量下Tb^(3+)的发光性能,并确定了Gd_(2)O_(3)更精确的最佳掺量范围。此外,文中通过改变气氛制备了Gd/Ce/Tb共掺杂氟氧化物玻璃,对比研究了Gd^(3+)和Ce^(3+)对Tb^(3+)的敏化作用。结果表明,本文所制备的氟氧化物玻璃都呈稳定的玻璃态;Gd^(3+)和Ce^(3+)对Tb^(3+)的发光都具有敏化作用,且Gd_(2)O_(3)掺量为7%(摩尔分数,下同)时敏化效果相较于其他掺量最为显著,超出7%则造成猝灭;Ce_(2)O_(3)掺入玻璃后以Ce^(3+)和Ce^(4+)两种价态共存,在还原气氛下掺入相较于空气气氛下掺入更容易保持Ce^(3+)状态,而且Ce^(3+)对Tb^(3+)的发光具有敏化作用,Ce^(4+)会抑制Tb^(3+)的发光。 展开更多
关键词 Tb^(3+)发光特性 Gd/Ce/Tb共掺 Ce^(3+)/Ce^(4+)价态 氟氧化物玻璃 能量传递
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A ratiometric fluorescent probe for hypoxanthine detection in aquatic products based on the enzyme mimics and fluorescence of cobalt-doped carbon nitride
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作者 Xin Wang Chengyi Hong +1 位作者 Zhengzhong Lin Zhiyong Huang 《Food Science and Human Wellness》 SCIE CSCD 2024年第2期879-884,共6页
A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition... A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products. 展开更多
关键词 Co doped g-C_(3)N_(4) Ratiometric fluorescent probe HYPOXANTHINE FRESHNESS Aquatic products
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Oxygen vacancy defects engineering on Cu-doped Co_(3)O_(4) for promoting effective COS hydrolysis 被引量:2
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作者 Guanyu Mu Yan Zeng +5 位作者 Yong Zheng Yanning Cao Fujian Liu Shijing Liang Yingying Zhan Lilong Jiang 《Green Energy & Environment》 SCIE EI CAS CSCD 2023年第3期831-841,共11页
The activation of H_(2)O is a key step of the COS hydrolysis,which may be tuned by oxygen vacancy defects in the catalysts.Herein,we have introduced Cu into Co_(3)O_(4) to regulate the oxygen vacancy defect content of... The activation of H_(2)O is a key step of the COS hydrolysis,which may be tuned by oxygen vacancy defects in the catalysts.Herein,we have introduced Cu into Co_(3)O_(4) to regulate the oxygen vacancy defect content of the catalysts.In situ DRIFTS and XPS spectra reveal that COS and H_(2)O are adsorbed and activated by oxygen vacancy.The 10 at%Cu doped Co_(3)O_(4) sample(10Cu-Co_(3)O_(4))exhibits the optimal activity,100%of COS conversion at 70℃.The improved oxygen vacancies of CueCo_(3)O_(4) accelerate the activation of H_(2)O to form active -OH.COS binds with hydroxyl to form the intermediate HSCO^(-)_(2),and then the activated-OH on the oxygen vacancy reacts with HSCO^(-)_(2) to form HCO^(-)_(3).Meanwhile,the catalyst exhibits high catalytic stability because copper species(Cu+/Cu^(2+))redox cycle mitigate the sulfation of Co_(3)O_(4)(Co^(2+)/Co^(3+)).Our work offers a promising approach for the rational design of cobalt-related catalysts in the highly efficient hydrolysis COS process. 展开更多
关键词 Oxygen vacancy COS hydrolysis In situ spectra Cu doped Co_(3)O_(4)
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Preparation of Sn-doped Ga_(2)O_(3) thin films and their solar-blind photoelectric detection performance
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作者 Lijun Li Chengkun Li +3 位作者 Shaoqing Wang Qin Lu Yifan Jia Haifeng Chen 《Journal of Semiconductors》 EI CAS CSCD 2023年第6期65-74,共10页
Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron s... Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron sputtering. The films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet visible spectroscopy, and the effect of annealing atmosphere on the properties of films was studied. The Ga_(2)O_(3) films changed from amorphous to β-Ga_(2)O_(3) after annealing at 900 °C. The films were composed of micro crystalline particles with a diameter of about 5–20 nm.The β-Ga_(2)O_(3) had high transmittance for wavelengths above 300 nm, and obvious absorption for solar-blind signals at 200–280 nm.The metal semiconductor metal type solar-blind detectors were prepared. The detector based on Sn-doped β-Ga_(2)O_(3) thin film annealed in N_2 has the best response performance to 254 nm light. The photo-current is 10 μA at 20 V, the dark-current is 5.76 pA,the photo dark current ratio is 1.7 × 10~6, the response rate is 12.47 A/W, the external quantum efficiency is 6.09 × 10~3%, the specific detection rate is 2.61 × 10~(12) Jones, the response time and recovery time are 378 and 90 ms, respectively. 展开更多
关键词 Sn doped Ga_(2)O_(3) RF magnetron sputtering solar-blind photodetector
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Upconversion Luminescence of Ce^(3+) Doped BK7 Glass by Femtosecond Laser Irradiation 被引量:3
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作者 汪晨 彭明营 +5 位作者 杨旅云 胡晓 达宁 陈丹平 朱从善 邱建荣 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第6期754-756,共3页
Near-infrared to visible upconversion luminescence was observed in a multicomponent silicate (BK7) glass containing Ce^3 + ions under focused infrared femtosecond laser irradiation. The emission spectra show that t... Near-infrared to visible upconversion luminescence was observed in a multicomponent silicate (BK7) glass containing Ce^3 + ions under focused infrared femtosecond laser irradiation. The emission spectra show that the upconversion luminescence comes from the 4f-5d transition of the Ce^3 + ions. The relationship between the intensity of the Ce^3 + emission and the pump power reveals that a three-photon absorption predominates in the conversion process from the near-infrared into the blue luminescence. The analysis of the upconversion mechanism suggests that the upconversion luminescence may come from a three-photon simultaneous absorption that leads to a population of the 5d level in which the characteristic luminescence occurs. 展开更多
关键词 femtosecond laser Ce^3 UPCONVERSION f-d transition multiphoton process rare earths
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Sol-gel processed Ce^(3+), Tb^(3+) codoped white emitting phosphors in Sr_2Al_2SiO_7 被引量:5
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作者 潘文 宁桂玲 +1 位作者 林源 杨雪峰 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第2期207-210,共4页
Sr2Al2SiO7:Ce^3+, Tb^3+ white emitting phosphors were fabricated using the sol-gel method. X-Ray Powder Diffraction (XRD) analysis confirmed the formation of Sr2Al2SiO7:Ce^3+, Tb^3+. Scanning Electron Microsco... Sr2Al2SiO7:Ce^3+, Tb^3+ white emitting phosphors were fabricated using the sol-gel method. X-Ray Powder Diffraction (XRD) analysis confirmed the formation of Sr2Al2SiO7:Ce^3+, Tb^3+. Scanning Electron Microscopy (SEM) observation indicated that the microstructure of the phosphor consisted of regular fine grains with an average size of about 0.5-1 μm. Luminescence properties were analyzed by measuring the photoluminescence spectra. The Ce^3+, Tb^3+-codoped Sr2Al2SiO7 phosphors showed four main emission peaks: one at 414 nm for Ce^3+ and three at 482, 543, and 588 nm for Tb^3+. The emission spectra of the samples with different doping concentrations showed that the Tb^3+ emission was dominant because of the persistent energy transfer from Ce^3+. The decay characteristic was better than that prepared by the solid-state process in the comparable condition. The codoped phosphor displayed long persistent white phosphorescence. 展开更多
关键词 sol-gel method luminescence PHOSPHORS Sr2Al2SiO7:Ce^3 Tb^3 rare earths
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Ab Initio Calculation of 4f→5d Transition Energy and Electronic Structure of Ce^(3+) Doped in LiYF_4 Crystal 被引量:2
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作者 蒋滢 曾雉 +1 位作者 夏上达 尹民 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第2期148-152,共5页
The electronic structures of LiYF4:Ce^3+ and LiYF4 crystal simulated by an embedded (in a microcrystal containing 1938 ions) cluster CeY4Li8F24, and Y5LisF24 respectively, were computed by the ab initio self-consi... The electronic structures of LiYF4:Ce^3+ and LiYF4 crystal simulated by an embedded (in a microcrystal containing 1938 ions) cluster CeY4Li8F24, and Y5LisF24 respectively, were computed by the ab initio self-consistent relativistic DV-Xa (discrete variational Xa) method. The ground-state calculation showed that only the lowest 5d level Ed of Ce^3+ ion lies around the BCB (bottom of the conduction band) while the lowest 4f levels is 2.5 eV lower than BCB. The CB states consist of 4d of Y mixed with 5d of Ce, even for the wavefunctions (WFS) with energy Ed under BCB there are still 24% of Y-4d and 9% of F-2p as components. So, they are not pure crystal-field states at all. Furthermore, transition state (TS) calculation was performed to obtain the 4f→5d transition energies Efd, to improve the previous calculation performed by Andriessen et al, in which a small CeF8 cluster embedded in an array of point charge was used and the results of ground-state calculation were roughly used to compare with the observed 4f→5 d transition energies. The ionic radius of Ce^3+ is larger than that of y^3+ , so we had also modeled approximately the lattice relaxation. As results, the CeY4Li8F24 cluster with 4.56 % outward relaxation (of the nearest-neighbor and next nearest-neighbor eight fluorines) has the lowest total energy and gave satisfactory 4f→5d energies Efd, but the ground-state calculated Ed is 0.68 eV higher than BCB. For another cluster with 7.36% outward relaxation the Ed is 0.43 eV lower than BCB, which makes the observation of fine structure (including zero-phonon line) of the lowest 5 d band understandable easier, but the splits between the transition energies Efd were not as good as the former. Therefore, we consider the relaxation is some how around 4. 56% -7.36% outward, not as large as 10% proposed by Andriessen et al. 展开更多
关键词 LiYF4 Ce^3 DV- Xa transition state 4f→5d embedded cluster rare earths
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Ab Initio Calculation of 4f→5d Transition Energy and Electronic Structure of Ce^(3+) Doped in LiYF_(4) Crystal
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作者 蒋滢 曾雉 +1 位作者 夏上达 尹民 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第4期405-405,共1页
The electronic structures of LiYF4:Ce^3+ and LiYF4 crystal simulated by an embedded (in a microcrystal containing 1938 ions) cluster CeY4Li8F24, and Y5LisF24 respectively, were computed by the ab initio self-consi... The electronic structures of LiYF4:Ce^3+ and LiYF4 crystal simulated by an embedded (in a microcrystal containing 1938 ions) cluster CeY4Li8F24, and Y5LisF24 respectively, were computed by the ab initio self-consistent relativistic DV-Xa (discrete variational Xa) method. The ground-state calculation showed that only the lowest 5d level Ed of Ce^3+ ion lies around the BCB (bottom of the conduction band) while the lowest 4f levels is 2.5 eV lower than BCB. The CB states consist of 4d of Y mixed with 5d of Ce, even for the wavefunctions (WFS) with energy Ed under BCB there are still 24% of Y-4d and 9% of F-2p as components. So, they are not pure crystal-field states at all. Furthermore, transition state (TS) calculation was performed to obtain the 4f→5d transition energies Efd, to improve the previous calculation performed by Andriessen et al, in which a small CeF8 cluster embedded in an array of point charge was used and the results of ground-state calculation were roughly used to compare with the observed 4f→5 d transition energies. The ionic radius of Ce^3+ is larger than that of y^3+ , so we had also modeled approximately the lattice relaxation. As results, the CeY4Li8F24 cluster with 4.56 % outward relaxation (of the nearest-neighbor and next nearest-neighbor eight fluorines) has the lowest total energy and gave satisfactory 4f→5d energies Efd, but the ground-state calculated Ed is 0.68 eV higher than BCB. For another cluster with 7.36% outward relaxation the Ed is 0.43 eV lower than BCB, which makes the observation of fine structure (including zero-phonon line) of the lowest 5 d band understandable easier, but the splits between the transition energies Efd were not as good as the former. Therefore, we consider the relaxation is some how around 4. 56% -7.36% outward, not as large as 10% proposed by Andriessen et al. 展开更多
关键词 LiYF4 Ce^3 DV- Xa transition state 4f→5d embedded cluster rare earths
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Spectral Properties and Sensitization of Ce^(3+) and Eu^(2+) Codoped Calcium Zinc Chlorosilicate
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作者 林海 刘行仁 张晓 《Journal of Rare Earths》 SCIE EI CAS CSCD 1998年第1期69-72,共4页
The Ce^3+ and Eu^2+ ions codoped calcium zinc chlorosilicate Ca_8Zn(SiO_4)_4Cl_2 phosphors have been synthesized for the first time. The diffuse reflection, excitation and emission spectra of Ca_8Zn(SiO_4)_4Cl_2∶Ce^3... The Ce^3+ and Eu^2+ ions codoped calcium zinc chlorosilicate Ca_8Zn(SiO_4)_4Cl_2 phosphors have been synthesized for the first time. The diffuse reflection, excitation and emission spectra of Ca_8Zn(SiO_4)_4Cl_2∶Ce^3+, Eu^2+ have been measured at room temperature. The luminescence sensitizaiton of Eu^2+ by Ce^3+ inCa_8Zn(SiO_4)_4Cl_2∶Ce^3+, Eu^2+ has been expounded under the excitation of ultraviolet light and the efficient nonradiative energy transfer from Ce^3+ to Eu^2+ in this system is confirmed. 展开更多
关键词 Rare earths Ce^3+ and Eu^2+ ions Calcium zinc chlorosilicate
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Spectral properties of Ce^(3+) doped yttrium lanthanum oxide transparent ceramics
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作者 杨秋红 周洪旭 陆神洲 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第2期186-189,共4页
Ce3+-doped yttrium lanthanum oxide (Y0.9La0.1)2O3 transparent ceramics is fabricated with nanopowders and sintered in H2 atmosphere. The spectral properties of Ce:(Y0.9La0.1)2O3 transparent ceramics are investig... Ce3+-doped yttrium lanthanum oxide (Y0.9La0.1)2O3 transparent ceramics is fabricated with nanopowders and sintered in H2 atmosphere. The spectral properties of Ce:(Y0.9La0.1)2O3 transparent ceramics are investigated. There appear two characteristic absorption peaks of Ce3+ ions at 230~nm and 400~nm, separately. It is found that Ce3+ ions can efficiently produce emission at 384~nm from (Y0.9La0.1)2O3 transparent ceramic host, while the emission is completely quenched in Re2O3 (Re=Y, Lu, La) host materials. 展开更多
关键词 Ce3 ion doped spectral property yttrium lanthanum oxide transparent ceramics
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CRYSTAL GROWTH AND MAGNETO OPTICAL PROPERTIES OF Ce^(3 +) DOPED IRONG ARNET
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作者 M.Huang1) and S.Y.Zhang2) 1) Department of Physics,Zhejiang University , Hangzhou 310027 ,China 2) Department of Materials Science & Engineering and State Key Laboratory of Silicon Materials,Zhejiang Uni versity , Hangzhou 310027 ,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1999年第4期353-356,共4页
Thispaperisconcerned withthe preparation ofcerium doped yttrium iron garnet which areknown to be an oxide withlarge magneto opticaleffect. Usingtheimproved flux method wesuccessfully grew the bulksinglecrystalsofiron... Thispaperisconcerned withthe preparation ofcerium doped yttrium iron garnet which areknown to be an oxide withlarge magneto opticaleffect. Usingtheimproved flux method wesuccessfully grew the bulksinglecrystalsofiron garnet doped by Ce 3 + ions with maximum substitution upto0 349. Here weinvestigatedthedifferentcomposition ofsolution for maxi mum Ce3 + substitution. Thespectra ofthe Faraday rotation andtheoptical absorption were measured inthenearinfrared region fordifferentCe3 + ionsdopediron garnets. The Cesub stitution prominentlyenhancesthe Faradayeffect,andthe Yb and Euionssubstitutefor Yinthe dodecahedralsitesof YIGcanincreasetheconcentration of Ce3 + ions, depresstheforma tion of nonmagnetic Ce4 + ionsbythechargecompensation. 展开更多
关键词 crystalgrowth Ce3 + doped iron Garnet magneto optical properties
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黄色荧光粉La_(3)Si_(6)N_(11)∶Ce^(3+)的结构、性能研究及第一性原理计算
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作者 林莹 刘梦丽 +3 位作者 陈文杰 高腾 胡晓琳 庄乃锋 《化工新型材料》 CAS CSCD 北大核心 2023年第2期164-168,共5页
运用高温固相法合成掺铈的氮化物荧光粉La_(3)Si_(6)N_(11)∶Ce^(3+)。采用X射线衍射仪、能谱仪、荧光光谱仪对合成样品的结构、发光性能等进行研究,利用Rietveld方法对其结构精修,并计算了La_(3)Si_(6)N_(11)∶Ce^(3+)的色坐标、色纯... 运用高温固相法合成掺铈的氮化物荧光粉La_(3)Si_(6)N_(11)∶Ce^(3+)。采用X射线衍射仪、能谱仪、荧光光谱仪对合成样品的结构、发光性能等进行研究,利用Rietveld方法对其结构精修,并计算了La_(3)Si_(6)N_(11)∶Ce^(3+)的色坐标、色纯度和色温。结果表明:该荧光粉的色坐标为(0.4165,0.558),落在黄绿光区域,计算得到La_(2.82)Si_(6)N_(11)∶Ce_(0.18)^(3+)的色纯度约为92.86%,具有较高的纯度,相关色温为4137K,属于中间色温。通过计算可得掺杂后La_(3)Si_(6)N_(11)∶Ce^(3+)的带隙值为2.92eV,相对掺杂前略微减少,且La_(3)Si_(6)N_(11)∶Ce^(3+)体系属于直接带隙结构,从而有利于提高其发光性能。 展开更多
关键词 La_(3)Si_(6)N_(11)∶Ce^(3+) XRD-Rietveld结构精修 发光性能 第一性原理计算
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8YSZ/Y_(3)Al_(5)O_(12):Ce^(3+)光敏复合热障涂层的等温氧化及光谱响应特性
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作者 何玲 蒲兵兵 +1 位作者 李文生 孙卫民 《材料保护》 CAS CSCD 2023年第3期13-19,48,共8页
为了监测热障涂层在氧化过程中陶瓷层内部的残余热应力,制备了Y_(3)Al_(5)O_(12):Ce^(3+)含量不同的8YSZ/Y_(3)Al_(5)O_(12):Ce^(3+)光敏复合热障涂层。研究了Y_(3)Al_(5)O_(12):Ce^(3+)不同含量下8YSZ/Y_(3)Al_(5)O_(12):Ce^(3+)光敏... 为了监测热障涂层在氧化过程中陶瓷层内部的残余热应力,制备了Y_(3)Al_(5)O_(12):Ce^(3+)含量不同的8YSZ/Y_(3)Al_(5)O_(12):Ce^(3+)光敏复合热障涂层。研究了Y_(3)Al_(5)O_(12):Ce^(3+)不同含量下8YSZ/Y_(3)Al_(5)O_(12):Ce^(3+)光敏复合热障涂层等温氧化过程的失效机理,阐述了陶瓷层内部残余热应力与Y_(3)Al_(5)O_(12):Ce^(3+)的发射光谱的峰值波长之间的内在响应机制;同时研究了8YSZ/Y_(3)Al_(5)O_(12):Ce^(3+)光敏复合热障涂层陶瓷层发射光谱峰值波长偏移量与氧化时间的关系,并拟合了8YSZ/10%Y_(3)Al_(5)O_(12):Ce^(3+)光敏复合热障涂层等温氧化时间与光谱变化的传感方程。结果表明:1 050℃等温氧化100 h过程中8YSZ/Y_(3)Al_(5)O_(12):Ce^(3+)光敏复合热障涂层失效主要是陶瓷层内部残余热应力导致,且随氧化时间的增加,陶瓷层内部残余热应力增加,Y3Al5O12:Ce3+的发射光谱的峰值波长向短波方向偏移;8YSZ/10%Y_(3)Al_(5)O_(12):Ce^(3+)光敏复合热障涂层发射光谱峰值波长偏移量与氧化时间传感方程为:Δλ=155.785 07·t0.004 15-154.792 58。因此,可以通过发射光谱峰值波长的偏移规律表征氧化过程中陶瓷层内部的残余热应力。 展开更多
关键词 热障涂层 Y_(3)Al_(5)O_(12):Ce^(3+) 等温氧化 残余热应力
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黄色荧光粉YAG:Ce^(3+)结构精修及发光性能
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作者 林莹 冯嘉雯 刘梦丽 《广州化工》 CAS 2023年第24期23-25,45,共4页
运用高温固相法在1 450℃合成系列掺铈的钇铝石榴石荧光粉Y_(3-x)Al_(5)O_(12):Ce_(x)^(3+),得到最佳样品为Y_(2.75)Al_(5)O_(12):Ce_(0.05)^(3+)。对样品进行X射线衍射、形貌特征、荧光光谱等方面的测试分析后,结果表明该荧光粉晶粒尺... 运用高温固相法在1 450℃合成系列掺铈的钇铝石榴石荧光粉Y_(3-x)Al_(5)O_(12):Ce_(x)^(3+),得到最佳样品为Y_(2.75)Al_(5)O_(12):Ce_(0.05)^(3+)。对样品进行X射线衍射、形貌特征、荧光光谱等方面的测试分析后,结果表明该荧光粉晶粒尺寸为15μm左右,各元素分布均匀,其精修图与实测XRD谱图基本吻合,属于立方晶系。色坐标为(0.645 1,0.354 5),色纯度达到94.04%,相关色温为3 770 K。通过能级分析,得出其斯托克位移Es为3 494 cm^(-1)。 展开更多
关键词 YAG:Ce^(3+) 结构精修 发光性能 能级分析
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