VACUUM
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2026
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IF 3.9
RuYin Deng,YanShu Huang,Shisong Liu,Jichuan Huo,Yong Cao
In this study, to our knowledge, this is the first systematic demonstration of a room-temperature to 200 °C PTCR window in La-doped LiTaO 3 with grain-boundary-dominated barriers. The results show that the solubility of La in LiTaO 3 was less than 15wt.%, and the La contents would affect the microstructure as well the electrical conductivity of LiTaO 3 . For the LiTaO 3 -based materials with/without La doping, the materials exhibit the PTCR jump (log (R max / R min )) of 2.6∼3.6 between room temperature and ∼200 °C, and varied with La contents. By combining impedance spectroscopy and time relaxation techniques, the complex impedance response of LiTaO 3 -based ceramic materials was analyzed, revealing multiple grain boundary resistances corresponding to relaxation processes with distinct time constants (τ) were the origin of the PTC effect.
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高影响因子
JOURNAL OF RARE EARTHS
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2026
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IF 9.6
Zhengren Tao,Lingying Xu,Yinghan Wang,Qingdi Liu,Shi Ye
Bulk ceramics of afterglow phosphors are preferred for real applications with applied external stimuli like electric field, force and heat. However, sintering powdered afterglow phosphors with high-temperature-volatile components to bulk form normally leads to deterioration or even loss of persistent luminescence (PersL), such as the case of LiTaO 3 :Tb 3+ . This study adopted a strategy of using nanosized precursors prepared by exfoliation and molten salts methods for the subsequent sintering procedure to form LiTaO 3 :1 mol% Tb 3+ bulk nanoceramics, which show outstanding PersL compared to bulk microceramics with absence of PersL. The dynamics of carriers, including electrons, holes and non-static V Li defects were detailedly investigated in the charging process of the bulk nanoceramics at elevated temperatures. It is found that defects not only act as traps storing and releasing electron-hole carriers, but also function as carriers themselves in the LiTaO 3 :1%Tb 3+ bulk nanoceramics. Temperature-dependent electricity and luminescence verify the hopping process of Li + / V Li above 225 °C . The hopping leads to accelerated release of holes initially captured by V Li and the subsequent non-radiative recombination with electrons from V O . It features an apparent and significant intensity decline during the charging process compared to low temperatures or cases without PersL. The bulk nanoceramics possess a temperature-triggered capability for anti-counterfeiting and information storage. These findings contribute to a strategy to fabricate bulk ceramics which are sensitive to sintering procedure, and provide valuable insights into the underlying mechanisms and the rational design of PersL materials.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2021
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IF 5.316
Xin Li,Xusheng Wang,Rui Hu,Yanxia Li,Xi Yao
We report a novel mechanoluminescent phosphor Li 1−x Ca x Si x Ta 1−x O 3 :0.01Pr 3+ (x = 0–0.04). The crystal structure, photoluminescence (PL), optical diffuse reflectance spectra, afterglow (AG), fluorescence decay curves, and mechanoluminescence (ML) properties were investigated. To clarify the defect types and the mechanoluminescence mechanisms, an X-ray photoelectron spectroscopy (XPS) and thermoluminescence curve (TL) were measured. The dopants Ca 2+ and Si 4+ ions occupied the Li+ and Ta 5+ sites, respectively. An optimal sample Li 0.98 Ca 0.02 Si 0.02 Ta 0.98 O 3 :Pr 3+ was obtained with great enhancement in mechanoluminescence intensity, higher than that of non-doped sample LiTaO 3 :Pr 3+ by 262%. And the compression threshold, over which the ML intensity could not maintain the linear increase, has also been greatly improved. Furthermore, the stable output of Tribo-L was achieved, which was visible to the naked eye. A probable mechanism was proposed to illustrate the mechanoluminescent process in Li1-xCaxSixTa1-xO3:0.01Pr3 + (x = 0–0.04). The study indicates that adjusting trap distribution by substituting host ions may be a novel way to develop high-quality mechanoluminescence.
研究领域:
材料科学
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光学
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DOI
高影响因子
ADVANCED MATERIALS
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2024
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IF 27.4
Hang Yang,Yi Wei,Haonan Ju,Xinru Huang,Jun Li,Wei Wang,Dengfeng Peng,Dong Tu,Guogang Li
Elastico-mechanoluminescence technology has shown significant application prospects in stress sensing, artificial skin, remote interaction, and other research areas. Its progress mainly lies in realizing stress visualization and 2D or even 3D stress-sensing effects using a passive sensing mode. However, the widespread promotion of mechanoluminescence (ML) technology is hindered by issues such as high stress or strain thresholds and a single sensing mode based on luminous intensity. In this study, a highly efficient green-emitting ML with dual-mode stress-sensing characteristics driven by microscale strain is developed using LiTaO 3 :Tb 3+ . In addition to single-mode sensing based on the luminous intensity, the self-defined parameter ( Q ) is also introduced as a dual-mode factor for sensing the stress velocity. Impressively, the fabricated LiTaO 3 :Tb 3+ film is capable of generating discernible ML signals even when supplied with strains as low as 500 µst. This is the current minimum strain value that can drive green-emitting ML. This study offers an ideal photonic platform for exploring the potential applications of rare-earth-doped elastico-ML materials in remote interaction devices, high-precision stress sensors, and single-molecule biological imaging.
研究领域:
材料科学
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光电子学
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传感器
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生物医学工程
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
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IF 5.8
Dezhao Meng,Fukang Chen,Xinyu Chen,Lishun Yang,Xing Zhao,Can Tian,Yuan Zhou,Li Jin,Vladimir Laletin,Chunlin Song,Yan Yan,Gang Liu
Ceramic materials with relaxor dielectric properties , expressed as (1- x )(0.94Na 0.5 Bi 0.5 TiO 3 -0.06LiTaO 3 )- x CaTiO 3 [(1- x )(NBT-LT)- x CT] with x values of 0.12, 0.15, 0.18, and 0.21, were synthesized through an A-site doping method to enhance energy storage capabilities. The linear dielectric CaTiO 3 was chosen as the acceptor additive, and ceramic samples were prepared using conventional solid-phase and molding techniques. A comprehensive investigation evaluated the influence of different CT concentrations on the phase and energy storage/release characteristics of NBT-LT. Optimal performance was notably achieved with a 15% CT doping concentration, resulting in W rec and η values of 2.16 J/cm³ and 70%, respectively, for a 100 μm thick sample under a 210 kV/cm voltage. When the film was rolled to a 60 μm thickness, the voltage strength increased to 330 kV/cm, leading to enhanced W rec (5.33 J/cm³) and η (80%). Within the temperature range of 30 °C to 150 °C, only a marginal change in W rec (less than 10%) was observed. Frequency conversion tests across the 1 Hz to 100 Hz range demonstrated the material's relative stability, with W rec exhibiting minimal fluctuations. These findings emphasize the outstanding temperature and frequency stability of the material. During discharge, the material displayed a power density of up to 152 MW/cm³, coupled with a discharge time of 0.3 μs, showcasing remarkable pulse discharge capabilities. The experimental results affirm the promising potential of (NBT-LT)-0.15CT lead-free relaxor ferroelectric ceramics for application in commercial capacitors.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
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