Energy Technology
·
2017
·Vol. 5
·期 9
·1656-1662
·
IF 2.789
Yifan Chen,Yangfan Lin,Ning Du,Chengmao Xiao,Shali Wu,Yaguang Zhang,Deren Yang
We report the synthesis of Zn 2 GeO 4 nanorods using a simple hydrothermal process. After the coating of a carbon layer by the thermal decomposition of acetylene gas, the Zn 2 GeO 4 @C core–shell nanorods were obtained. The as-synthesized Zn 2 GeO 4 @C core–shell nanorods were used as anode materials of lithium-ion batteries, which showed good cycling and rate performance. A highly reversible specific capacity of 718 mAh g −1 after 400 cycles was achieved at a current density of 400 mA g −1 . The core–shell nanostructures and partially amorphous and porous nanostructures helped to alleviate the volume change and enhance the conductivity during the charge/discharge process, which may be responsible for the good performance.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Siyi Yu,Xinyu Gong,Dongxin Shi,Mengchao Xue,Yuanyuan Zhang,Keke Han,Na Li,Guiqin Hou,Fengfeng Li
Traditional anti-counterfeiting materials have the characteristics of static display of anti-counterfeiting patterns and are easy to be disturbed by background patterns. Consequently, the development of novel luminous materials represents an imperative objective. As a novel class of matrix material, Sr 3 Y 2 Ge 3 O 12 has demonstrated considerable potential for application in the field of anti-counterfeiting. In this study, strontium yttrium germanate doped manganese ion long afterglow material was prepared by the high temperature solid phase method, and its afterglow performance and dynamic anti-counterfeiting application were studied. The experimental results show that the sample exhibits excellent luminescence characteristics. It is observed that the sample excited at 260 nm shows an emission band centred at 634 nm and a high-energy turning point at 578 nm. Using screen printing technology, design a variety of anti-counterfeiting labels. The prepared samples after ultraviolet excitation can maintain the pattern for a long time, and with the passage of time, the pattern shows dynamic attenuation, which is important in enhancing the anti-counterfeiting effect and improving product safety.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2015
·
IF 2.679
Na Kong,Hui-Hui Zhang,Jie Wang,Zhi-Hong Liu
Two pure dehydrated borogermanates with microporous structure, β -K 2 [B 2 Ge 3 O 10 ] and NH 4 [BGe 3 O 8 ], have been synthesized and characterized by XRD, FT-IR, TG techniques. The molar enthalpies of solution of 2.51 mg of GeO 2 (s)/0.99 mg of H 3 BO 3 (s)/1.98 mg of H 3 BO 3 (s) in 2.00 cm 3 of 1 mol · dm −3 NaOH (aq) were measured, respectively. The molar enthalpies of solution of 2.44 mg of K 2 B 4 O 7 · 4H 2 O (s) and 2.18 mg of NH 4 B 5 O 8 · 4H 2 O (s) in the mixture solvent of 2.00 cm 3 of 1 mol · dm −3 NaOH (aq) which contains 2.51 mg of GeO 2 (s) were measured, respectively. The molar enthalpies of solution of 3.82 mg of β -K 2 [B 2 Ge 3 O 10 ] (s) in the mixture solvent of 2.00 cm 3 of 1 mol · dm −3 NaOH (aq) which contains 0.99 mg of H 3 BO 3 (s), and 3.00 mg of NH 4 [BGe 3 O 8 ] (s) in the mixture solvent of 2.00 cm 3 of 1 mol · dm −3 NaOH (aq) which contains 1.98 mg of H 3 BO 3 ) (s) were also measured, respectively. With the use of standard molar enthalpies of formation for NH 4 B 5 O 8 · 4H 2 O (s), K 2 B 4 O 7 · 4H 2 O (s), GeO 2 (s), H 3 BO 3 (s) and H 2 O (l), the standard molar enthalpies of formation of – (3937.1 ± 4.7) kJ · mol −1 for β -K 2 [B 2 Ge 3 O 10 ] and – (2713.7 ± 6.0) kJ · mol −1 for NH 4 [BGe 3 O 8 ] at T = 298.15 K were obtained on the basis of the appropriate thermochemical cycles, respectively.
研究领域:
无机化学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 29
·1-12
·
IF 2.8
Zhang Zeqing,Liu Wei,Li Lin,Li Huan,Zhang Zhijun,Cheng Shuai,Rao Guanghui,Zhao Jingtai
In recent years, materials exhibiting multimodal luminescence properties from deep red to near-infrared (NIR) wavelengths have been a focal point of research, particularly in the exploration of applications within the realms of stress sensing and dynamic signature anti-counterfeiting. A pyroxene-type layered crystal structure compound, CaMgGe 2 O 6 : Mn 2+ , has been reported as a mechanoluminescent (ML) material. Upon incorporation into the host, Mn 2+ ions preferentially substitute for Mg 2+ ions, emitting deep red to near-infrared light (600–800 nm) within this six-coordinated [MgO 6 ] octahedral environment. The congruence of photoluminescence and ML spectra indicates that both types of luminescence originate from the same emissive center. The doping of Mn 2+ ions introduces impurity band, effectively reducing the optical band gap, as evidenced by ultraviolet diffuse reflectance measurements. Thermoluminescence results reveal three defect centers within the phosphor, whose concentrations decrease with Mn 2+ doping, correlating with a reduction in ML intensity. The ML mechanism of the phosphor is elucidated through the analysis of local piezoelectric properties within the crystal. Overall, this study may pave new pathways for the development of efficient near-infrared mechanoluminescent materials, showcasing potential applications within the biological domain.
研究领域:
材料科学
·
光学
·
生物医学工程
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 17
·5458-5464
·
IF 6.1
Nan Zhang,Mei Yang,Wen-Dong Yao,Wei Xu,Wenfeng Zhou,Wenlong Liu,Sheng-Ping Guo
Rational structural design and modification based on known compounds is an effective strategy to explore new nonlinear optical (NLO) materials. Here, three new rare-earth (RE) oxythiogermanates Eu18Ge9O5S31 (1), Ca3.32Eu14.68Ge9O5S31 (2) and Ba3Eu15Ge9O5S31 (3) were obtained by the novel cation and anion co-partial substitution strategy from the parent β-Eu2GeS4 (0), which induces centrosymmetric to noncentrosymmetric (NCS) structural transformation and NLO activities. They crystallize with a pseudo-zero dimensional structure in the chiral R3 space group, featuring almost linearly arranged isolated GeS4 and GeOS3 tetrahedra. Their optical band gaps were determined to be 2.18, 2.23 and 2.24 eV, respectively. 1 and 2 show balanced NLO properties with moderate second-harmonic generation (SHG) responses (0.5 and 0.6 × AGS) and high laser-induced damage thresholds (LIDTs) (3.3 × AGS). Moreover, theoretical calculations show that their NLO properties are determined by the synergistic effect of GeS4 and GeOS3 tetrahedra. This work enriches the chemistry of rarely studied RE oxychalcogenides and provides a fresh route for designing NCS structures targeting diverse applications.
研究领域:
材料科学
·
晶体学
·
光学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2024
·Vol. 130
·期 7
·1-7
·
IF 2.5
Xing Zhuo,Song Julong,Pan Hong,Wang Juan
A series of CaMgGe 2 O 6 ceramics doped with Zn 2+ ions were designed and fabricated using the solid-state reaction method. The impact of cation doping on sintering behavior, crystal structure, microstructure, and dielectric properties was systematically investigated. Incorporating Zn 2+ ions into the crystal structure optimized the sintering process to enhance densification. Analysis of the crystal structure revealed slight changes in lattice parameters and unit cell volume upon introduction of Zn 2+ dopants, indicating successful incorporation without significant alteration to the overall structure. Microstructural characterization revealed that increasing Zn 2+ content resulted in a finer microstructure with a more uniform grain size distribution. Furthermore, substitution of Zn 2+ effectively reduced dielectric loss in CaMgGe 2 O 6 ceramics while maintaining a stable dielectric constant, making them suitable for high-frequency applications. Among all compositions tested, CaMg 0.8 Zn 0.2 Ge 2 O 6 exhibited exceptional performance with a Q × f value reaching 64,980 GHz along with an ε r of 7.88 and τ f of -36.9 ppm/°C.
研究领域:
材料科学
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2025
·
IF 3.3
Tingting Yan,Dinghan Jin,Dongyang Xi,Lei Sun,Linan Liu,Han Li
NaHoGeO 4 crystals were successfully synthesized under hydrothermal conditions. The crystals had petal-like morphologies with dimensions of approximately 300 μm. The crystals displayed excellent luminescent properties, appearing yellow under natural light and pale red under UV light irradiation. Compared with solid-state synthesis method, these experiments require a shorter time and can be operated at a lower temperature. To assess the structural integrity of NaHoGeO 4 and its luminescent characteristics under varying pressure conditions, a diamond anvil cell (DAC) was utilized to perform high-pressure Raman and photoluminescence (PL) spectroscopic studies. The results of high-pressure PL spectroscopy demonstrated that NaHoGeO 4 probably underwent a structural transformation into a new phase within 5.7–9.0 GPa. High-pressure Raman analysis indicated that notable alterations occurred throughout the assessed pressure spectrum, indicating that a phase transition took place. When the pressure was increased to approximately 15.0 GPa, the high-pressure phase of NaHoGeO 4 (NaHoGeO 4 -HP) remained stable. Once the pressure was reduced, the spectra reverted to their initial forms, suggesting that the phase transition could be reversed. This study provides a new approach for the study of the luminescent properties of rare-earth germanate compounds, with significant potential for practical applications.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2022
·Vol. 20
·期 3
·1953-1962
·
IF 2.328
Quansheng Wu,Shanshan Ye,Xufeng Zhou,Jianyan Ding
Developing narrowband red phosphors has always been a frontier topic in the phosphor community. In this study, a novel hafnium germanate red phosphor, BaHfGe 3 O 9 :Eu 3+ , was successfully synthesized by solid-state reaction method. The phase and crystal structure of BaHfGe 3 O 9 were investigated by the Rietveld refinement of powder X-ray powder diffraction. The band structure was analyzed by density functional theory calculations. Most importantly, the luminescence behavior of phosphors under near-ultraviolet (n-UV) light and cathode rays sources was studied in detail to explore the possibility of their applications in white light-emitting diodes and field emission display. The BaHfGe 3 O 9 :Eu 3+ phosphor exhibits strong f–f excitation and excellent thermal robustness due to Eu 3+ localization in the rigid lattice and asymmetric Ba 2+ sites. Under cathode rays and n-UV light excitation, BaHfGe 3 O 9 :Eu 3+ exhibits narrowband red light emission peaked at 610 nm. Moreover, BaHfGe 3 O 9 :Eu 3+ shows excellent saturation resistance and aging resistance. The performance of the LED lamp encapsulated by the BaHfGe 3 O 9 :Eu 3+ phosphor was studied. The results show that BaHfGe 3 O 9 :Eu 3+ is a potential red phosphor for multifunctional applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Ying Lv,Ning Zhao,Chaofeng Li,Cunjian Lin,Shihai You
Efficient and stable persistent phosphors play a crucial role in the fields of energy storage, anti-counterfeiting, and biomedical fields. Here, we present an improved synthetic method for preparing a series of color-tunable LiYGeO 4 :Tb 3+ persistent phosphor. The increased Tb 3+ concentration in the improved method enhances the persistent luminescent intensity at 20 s by ∼2.96 times. This enhancement is due to the dual roles of Tb 3+ as both emitters and trap centers within LiYGeO 4 . By simply increasing the doping concentrations, the persistent color can be adjusted from blue to green. LiYGeO 4 :Tb 3+ exhibits no loss of persistent luminescent intensity even after exposure to water at 80 °C for 72 h, surpassing the commercial green persistent phosphor. Furthermore, information storage was successful demonstrated by using LiYGeO 4 :Tb 3+ with various doping concentrations. This study represents a significant advancement in optimizing the properties of persistent luminescent materials, where dopants simultaneously serve as emitters and trap centers.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2014
·
IF 1.716
Xijia He,Xuhui Xu,Youming Shi,Jianbei Qiu
The Ag ions were introduced into the Bi doped silicogermanate glasses by Ag + for Na + ion exchange method. After ion exchange, the X-ray photoelectron spectroscopy (XPS) spectrum implied the Ag ions were mainly in ionic form (Ag + ) within the glasses. With the increase of the Ag + concentration, more relaxation of local structure would be induced at the non-bridging oxygen (NBO), meaning that the network gave more negative sites. Bi 3+ ions could be reduced to lower valence states of Bi containing Bi near infrared (NIR) active centers with the depolymerization of glass network, resulting in the enhancement of the Bi NIR luminescence. After heat treatment, the XPS, absorption spectra and transmission electron microscope (TEM) images revealed Ag nanoparticles (Ag NPs) formed in glasses. With the increase of the Ag NPs concentration, more NBOs released from Ag + , which led to reduce more Bi 3+ ions to lower valence states of Bi containing Bi NIR active centers, resulting in further enhancement of the NIR luminescence. Our research may extend the understanding of structural modulation in Bi valence states and offer a valuable way to enhance the NIR luminescence of Bi in glasses.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 9
·2681-2689
·
IF 6.1
Jiazheng Zhou,Hongshan Wang,Junjie Liu,Xin Su,Yu Chu,Jiale Qu,Xiangzhan Jiang
Two new thiohalides Pb3GeS4Br2 and Pb3.5GeS4Br3 have been synthesized by introducing Pb2+ into the thiogermanate system. The compounds crystallize in centrosymmetric P21/c (Pb3GeS4Br2) and non-centrosymmetric P63 (Pb3.5GeS4Br3) space groups, respectively. To the best of our knowledge, Pb3GeS4Br2 and Pb3.5GeS4Br3 are the first Pb-containing thiogermanate halides, and the latter is the first phase-matching IR nonlinear optical material in the thiogermanate halide system. Due to the presence of Pb2+ with stereochemically active lone pair electrons, Pb3GeS4Br2 exhibits a strong optical anisotropy with a birefringence of 0.131@1064 nm, while Pb3.5GeS4Br3 shows a large second-harmonic generation response (0.8 × AgGaS2) and high laser-induced damage threshold (3.0 × AgGaS2). These results enrich the structural and chemical diversity of chalcohalides.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Lu Pan,Yafang Wang,Wanting Wang,Mengting Zhao
Near-infrared (NIR) long persistent luminescent materials, with broad potential applications, have attracted significant research interest, though most studies focus on room-temperature performance. However, designing and synthesizing long-persistent luminescent materials that can form a large number of stable shallow traps at lower temperatures is extremely challenging. In this paper, a series of Cr-doped broadband near-infrared silicon germanate long persistent luminescent phosphors were synthesized by the high-temperature solid-phase method. The optical properties and crystal structural parameters of the phosphors at room temperature were studied systematically. The specific luminescence sources and reasons for the broadening of emission peaks have been discussed. The significant differences in persistent luminescence at different temperatures are caused by the substitution of Ge-Si chemical units in the Na₂CaGe x Si 6-x O₁₄ matrix doped with Cr³⁺ ions. Among the samples, Na 2 CaGe 4 Si 2 O 14 :0.4 mol% Cr 3+ shows excellent persistent luminescence properties and abundant shallow traps at low temperature. This phosphor was tested at low temperature to investigate its potential as an indicator for the temperature changes of biologics.
研究领域:
材料科学
·
光学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）