Author Affiliations
Abstract
1 School of Physics and Electronic-Information Engineering, Hubei Engineering University, Xiaogan 432000, China
2 School of Materials and Architectural Engineering, Guizhou Normal University, Guiyang 550025, China
3 School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
(SMO) thin films are deposited on substrates by magnetron sputtering. The effects of ambient temperature on the structural, electrical, and optical properties of the films are investigated. As the temperature increases from 23°C to 800°C, the SMO film exhibits high crystallinity and low electrical resistivity, and the real part of dielectric functions becomes less negative in the visible and near-IR wavelength range, and the epsilon near zero (ENZ) wavelength increases from 460 nm to 890 nm. The optical loss of the SMO film is significantly lower than that of Au, and its plasmonic performance is comparable to or even higher than TiN in the temperature range of 23°C to 600°C. These studies are critical for the design of high-temperature SMO-based plasmonic devices.
plasmonic materials strontium molybdate thin films optical losses temperature Chinese Optics Letters
2023, 21(5): 053601
1 重庆交通大学交通运输学院，重庆 400074
2 重庆交通大学土木工程学院，重庆 400074
3 重庆交通大学材料科学与工程学院，重庆 400074
长余辉材料应用广泛，但种类繁多、发光机理难以被普遍阐释。针对发光-余辉性能好的Sr2MgSi2O7:Eu2+,Dy3+硅酸盐长余辉材料，构建Sr2MgSi2O7基质、Eu掺杂及(Eu,Dy)共掺杂Sr2MgSi2O7的分子模型，进行第一性原理计算。从电子结构角度解译电子跃迁俘获路径，并阐释Sr2MgSi2O7:Eu2+,Dy3+的持续发光机理。结果表明：Eu、Dy离子的掺入使Sr2MgSi2O7由间接带隙半导体转变为直接带隙半导体；Dy 5d态主要位于Fermi能级与Eu 5d态之间，并与Eu 5d态存在能量重叠，这证实了Dy3+作为电子陷阱的合理性。Sr2MgSi2O7:Eu2+,Dy3+发光过程的揭示有助于后续光学性能的调控与提升。
硅酸镁锶长余辉材料 第一性原理计算 发光机理 电子跃迁俘获 magnesium strontium silicate long afterglow materi first-principles calculation luminescence mechanism electron transition capture
1 武汉大学物理科学与技术学院, 武汉 430064
2 中国地质大学 (武汉)材料与化学学院, 武汉 430070
3 武汉大学苏州研究院, 江苏苏州 215125
Sr3Sn2O7:Sm3+是一种被广泛研究的应力法光材料, 但关于 Sm3+掺杂量的研究仍然存在缺失。本工作采用高温固相法制备 Sr3-xSn2O7:xSm3+。在 Sr3Sn2O7中掺入少量 Sm3+后, 样品仍然保持着非中心对称的双钙钛矿结构。样品在受到紫外灯激励或应力施加之后, 能展现出稳定的光致发光、长余辉和应力发光性能, 且这三者的光谱显示出一致性。应力发光来源于 Sm3+的 4G5/2激发态向 6HJ (J=5/2, 7/2, 9/2)基态的电子跃迁。通过调控 x值对其发光性能进行优化, 在 x=0.020时性能昀好。Sm3+掺杂量的变化对应力发光性能的影响, 既对现有的相关工作进行了补充, 同时也能为未来的相关研究起到参考或指导的作用。
锡锶氧化物 三价钐离子 双钙钛矿 应力发光 tin strontium oxide trivalent samarium ion double perovskite mechanoluminescence
1 华南农业大学工程学院，广州 510640
2 华南理工大学，广东省燃料电池技术重点实验室，广州 510640
3 广东贝源检测技术股份有限公司，广州 510663
直接碳固体氧化物燃料电池(DC-SOFC)银基阳极具有高化学稳定性和抗硫抗积碳性能，然而受制于较差的催化性能，使得DC-SOFC的电化学性能一直无法让人满意。锶钴掺杂铁酸镧(LSCF)是一种催化性能佳，且兼具电子电导和离子电导的电极材料。通过LSCF修饰DC-SOFC的银基阳极(银-钆掺杂的氧化铈，Ag-GDC)，显著提高了银基阳极的催化性能和相应的电池输出性能。在850 ℃，对应的DC-SOFC的最大功率密度由224 mW/cm2提高264 mW/cm2。相应的半电池阻抗谱、电极材料的微观形貌和晶型结构、与恒电流放电测试表明，在LSCF修饰后，Ag-GDC的极化阻抗由0.543 Ω·cm2降低至 0.373 Ω·cm2，电极的微观形貌和晶型结构稳定，对应电池的燃料利用率由51.3%提升至57.9%。因此，LSCF修饰的Ag-GDC是一种性能良好且化学稳定的DC-SOFC理想阳极材料，有望推动DC-SOFC技术的进一步发展。
固体氧化物燃料电池 直接碳燃料电池 银基阳极 锶钴掺杂铁酸镧 复合阳极 solid oxide fuel cell direct carbon fuel cell silver anode strontium cobalt doped lanthanum ferrite composed anode
Author Affiliations
Abstract
1 Research and Technology Unit, FGI SPA SET of the MIA RF, Rostov-on-Don, 344000, Russia
2 Research Institute of Physics, Southern Federal University, 194 Stachki Ave., Rostov-on-Don, 344006, Russia
The properties studying results of ceramics based on strontium, calcium and sodium niobates, which vary from the conditions of synthesis, sintering, and mechanical processing, are presented. The evolution of the grain structure of objects is traced depending on their phase filling during concentration changes in the composition and thermodynamic prehistory (preparation conditions).The properties studying results of ceramics based on strontium, calcium and sodium niobates, which vary from the conditions of synthesis, sintering, and mechanical processing, are presented. The evolution of the grain structure of objects is traced depending on their phase filling during concentration changes in the composition and thermodynamic prehistory (preparation conditions).
Layered perovskite-like compounds binary systems pyroniobates of calcium and strontium microstructure mechanoactivation Journal of Advanced Dielectrics
2022, 12(1): 2160010
Author Affiliations
Abstract
1 State Key Laboratory for Mesoscopic Physics & Department of Physics, Collaborative Innovation Center of Quantum Matter & Frontiers Science Center for Nano-optoelectronics, Beijing Academy of Quantum Information Sciences, Peking University, Beijing 100871, China
2 Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Kaiserslautern 67663, Germany
3 College of Physics Science & Technology, Hebei University, Baoding 071002, China
4 Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
![]()
![]()
The two-dimensional electron gas (2DEG) generated at the LaAlO3/SrTiO3 interface has been in the focus of oxides research since its first discovery. Although oxygen vacancies play an important role in the generation of the insulator-to-metal transition of the SrTiO3 bare surface, their contribution at the LaAlO3/SrTiO3 interface remains unclear. In this work, we investigated a LaAlO3/SrTiO3 heterostructure with regional distribution of defect-based localized polar sites at the interface. Using static and time-resolved threshold photoemission electron microscopy, we prove that oxygen vacancies are induced near those polar sites, resulting in the increase of carrier density of the 2DEG states. In addition, oxygen-related surface states were uncovered, which we attributed to the release of lattice oxygen during the formation of oxygen vacancies. Such effects are mainly found spatially located around the defect sites at the buried interface, while other regions remain unaffected. Our results confirm that the itinerant electrons induced by oxygen vacancies can coexist with the charge transfer mechanism in the LaAlO3/SrTiO3 heterostructure, together leading to the formation of the metallic interface. These observations provide fundamental insights into the nature of LaAlO3/SrTiO3 interface based 2DEG and unique perspectives for potential applications.
two-dimensional electron gas photoemission electron microscopy strontium titanate defect states Opto-Electronic Science
2022, 1(7): 210011
1 江苏大学材料科学与工程学院, 镇江 212000
2 江苏大学土木工程与力学学院, 镇江 212000
0-3型钛酸锶钡(BST)与聚四氟乙烯(PTFE)复合材料是一种新型的陶瓷/高聚物功能复合材料, 可以兼具BST材料与PTFE材料的优点, 可表现出较高的介电常数和介电可调性。但是受聚合物相介电常数低的限制, 常规方法(流延法)制备的以聚合物为基体, 以陶瓷为填充相的复合材料的介电常数基本在100以下。为了进一步提高BST/PTFE复合材料的介电性能, 本研究采用一种新型烧结工艺--冷烧结工艺实现BST陶瓷与PTFE高聚物的共烧。在试验中以BST为基体, 引入体积比例为5%的PTFE, 并引入固相八水合氢氧化钡(Ba(OH)2·8H2O)作为过渡液相以辅助烧结过程进行, 制备0-3型BST/PTFE复合材料, 并探究了不同冷烧结条件下复合材料的介电性能。结果表明, 复合材料样品在冷烧结温度为275 ℃,压力为200 MPa,时间为2.5 h的条件下, 介电常数可达到500以上(25 ℃,1 kHz)。相对于常规制备工艺, 冷烧结工艺制备出的复合材料的介电常数有很大改进, 这对陶瓷/高聚物功能复合材料的低温制备与研究有一定参考意义。
钛酸锶钡 聚四氟乙烯 八水合氢氧化钡 冷烧结 微观形貌 介电性能 barium strontium titanate polytetrafluoroethylene Ba(OH)2·8H2O cold sintering micro morphology dielectric property
光学 精密工程
2022, 30(11): 1337
锶元素是人体不可缺少的微量元素, 饮用富锶矿泉水可以为人体补充锶。 目前用于检测富锶矿泉水中锶元素的常规分析方法如原子吸收光谱法、 原子荧光光谱法、 离子色谱法、 电感耦合等离子体-原子发射光谱法/质谱法等, 具有检测灵敏度高、 检测稳定性好的优点, 但是相关仪器体积庞大, 价格昂贵, 能耗高, 有些还需要使用惰性/特殊气体, 不适合现场、 实时和在线连续监测。 因此, 发展小型化、 低成本、 快速的光谱检测对锶元素的有效测量具有重要意义。 溶液阴极辉光放电-原子发射光谱法是近年来发展迅速的水体金属离子测量方法, 具有检出限低、 成本低、 小型化等优点。 因此, 建立溶液阴极辉光放电-原子发射光谱系统, 实现了富锶矿泉水中锶元素的浓度测量。 实验考察了溶液阴极辉光放电装置中放电电流、 溶液流速和pH值等参数对锶的信背比的影响, 确定了定量分析元素锶的最佳实验条件: 溶液流速1.85 mL·min-1、 溶液阴极辉光放电装置的放电电流75 mA, pH 1.0的HNO3作为电解质。 选取波长为460.77 nm的光谱线作为锶元素的分析谱线。 在上述最佳工作条件下对锶的溶液进行测定, 锶元素的发射光谱稳定性为0.52% (n=21)。 锶的质量浓度在0.1~20 mg·L-1范围内与其发射强度呈线性关系, 线性相关系数为0.999 6。 所建立的溶液阴极辉光放电-原子发射光谱法测得锶的检出限为29 μg·L-1。 采用搭建的溶液阴极辉光放电-原子发射光谱检测系统测量了市场上常见的三种富锶矿泉水, 测量结果与电感耦合等离子体发射光谱法一致。 此外, 该方法对富锶矿泉水的加标回收率为98.8%~107.6%。 结果表明: 溶液阴极辉光放电-原子发射光谱法是测定富锶矿泉水中锶的一种有效方法。
溶液阴极辉光放电-原子发射光谱 矿泉水 锶 检测 Solution cthode gow dscharge Mineral water Strontium Detection
Author Affiliations
Abstract
1 Lugansk State Pedagogical University, No. 2 Oboronnaya Street, Lugansk 91000, Ukraine
2 Research Institute of Physics, Southern Federal University, No. 194 Stachki Avenue, Rostov-on-Don 344090, Russia
3 Federal State Budgetary Institution of Science “Federal Research Centre, The Southern Scientific Centre of the Russian Academy of Sciences”, No. 41 Chekhova Street, Rostov-on-Don 344090, Russia
The research findings of the phase composition, nanostructure and optical properties of strontium–barium niobate thin films are discussed. BaNb2O6 nanosized films ( = 0.5 and 0.61) were characterized by XRD, SEM and AFM studies. Reflective multi-angle ellipsometry and spectrophotometry were used to determine the optical parameters (refractive index, its dispersion, and thickness of the damaged surface layer) of thin films. It was shown that SBN-50 and SBN-61 thin films were grown -oriented on Al2O3 (0001) and heteroepitaxial on MgO (001) substrates. The increase of refractive index, approaching its maximum value in the bulk material for a given composition as the film thickness increases, is observed.The research findings of the phase composition, nanostructure and optical properties of strontium–barium niobate thin films are discussed. BaNb2O6 nanosized films ( = 0.5 and 0.61) were characterized by XRD, SEM and AFM studies. Reflective multi-angle ellipsometry and spectrophotometry were used to determine the optical parameters (refractive index, its dispersion, and thickness of the damaged surface layer) of thin films. It was shown that SBN-50 and SBN-61 thin films were grown -oriented on Al2O3 (0001) and heteroepitaxial on MgO (001) substrates. The increase of refractive index, approaching its maximum value in the bulk material for a given composition as the film thickness increases, is observed.
Ellipsometry optical parameters strontium–barium niobates thin films Journal of Advanced Dielectrics
2021, 11(5): 2160014
