JOURNAL OF PHYSICS-CONDENSED MATTER
·
2016
·Vol. 28
·期 47
·475501
·
IF 2.209
LiDong Dai,Lei Wu,HePing Li,HaiYing Hu,YuKai Zhuang,KaiXiang Liu
The electrical transport properties of undoped and yttrium-doped strontium titanate (Sr(Ti1 – xYx)O3 – δ, x = 0, 0.02) under high pressure were investigated with in situ impedance spectroscopy measurements. A pressure-induced conductivity switching for undoped and 2 mole% Y-doped strontium titanate is observed at around ~10.0 and 7.0 GPa respectively, which are caused by a cubic to tetragonal I4/mcm phase transition. The decrease of the phase transition point of 2 mole% Y-doped strontium titanate can be attributed to larger Y3+ atoms occupying the B-site and the creation of more oxygen vacancies, which lead to octahedra tilting and symmetry breaking. The results of the voltage-bias dependence of grain-boundary impedance of undoped and 2 mole% Y-doped strontium titanate at different pressures revealed that Schottky-type potential barriers formed at grain boundaries are the key factor for the accumulation of oxygen vacancy at the interface under pressure.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Yusheng Yang,Bai Sun,Guangdong Zhou,Chuan Ke,Jie Zhang,Yongzan Zhou,Shuangsuo Mao,Jiajia Qin,Yong Zhao
Since memristors have shown great application prospects in non-volatile memory, neural synapse, brain-like chips, artificial intelligence (AI) and quantum computers, the research of memristors has received extensive attention. In this work, the resistive switching (RS) device with Ag/SrTiO 3 (STO)/Ti structure was fabricated, and it can significantly improve the RS performance of device by doping Mn ions into STO to replace part of Ti ions . That is to say, the Ag/Mn-doped SrTiO 3 (SMTO)/Ti device exhibits larger resistance window and better retention at room temperature. Finally, through in-depth mechanistic analysis, a physical model of the conducting filament and Schottky emission was established to understand the charge transport mechanism and RS behavior of the device. In particular, it provides favorable factors for the migration of ions and electrons through the Mn doping because the substitution of Mn for Ti ions reduces the volume of the STO crystal while distorting its crystal shape since the ionic radius of Mn is smaller than that of Ti. This work provides an important way to improve the RS properties of ABO 3 -type perovskite-based resistive random access memory (RRAM), and helps to explore the cutting-edge applications of high-performance RS devices in information processing and AI.
研究领域:
材料科学
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电子工程
·
人工智能
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2025
·
IF 3.2
Yushuai Jia,Liping Xu,Jiale Chen,Yueyuan Zeng,Zhihong Duan,Taifeng Liu,Xin Liu
Defect engineering can effectively promote light absorption and carrier dynamics of semiconductor photocatalysts. However, it is still difficult to modulate the distribution and concentration of defects in the photocatalyst via a facile strategy. The perovskite SrTiO3 is a promising semiconductor photocatalyst for hydrogen production, but its performance is restricted by limited UV absorption and severe carrier recombination. Herein, we develop a visible light-responsive SrTiO3 photocatalyst with Ti3+ and oxygen vacancies distributed both in the bulk and on the surface through a solvothermal synthesis coupled with light illumination. In situ EPR and XPS disclose that bulk defects are produced during the solvothermal synthesis, while the surface defects can be generated by light irradiation. The concentration of Ti3+ and oxygen vacancies can be facilely adjusted by varying the solvothermal time, resulting in the regulation of visible absorption in the range of 450–650 nm. Density functional calculations demonstrate the formation of an in-gap band consisting of defect energy levels, which induces a two-step electron transition and accounts for the visible light response. As revealed by synchrotron radiation X-ray absorption spectroscopy, ultrafast transient absorption spectroscopy, and electrochemical analysis, the increase of defect concentration leads to the decrease of Ti–O coordination number as well as the increase of carrier lifetime and carrier density, which ensures promoted carrier dynamics and boosted hydrogen evolution activity driven by visible light. The present research uncovers the role of defects in tuning light absorption and carrier dynamics and opens new opportunities for achieving highly efficient solar energy conversion.
研究领域:
材料科学
·
能源化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2024
·
IF 5.2
Jiaqi He,Jiao Han,Menghong Li,Mingwei Li,Ju Zhou,Ping Yang,Shiqi Li,Wenhan Qi,Zehui Lin,Gang Wang,Yiming Zeng,Li Chen
A series of Sr 1‒1.5 x Lu x TiO 3 ( x = 0, 0.005, 0.01, 0.015, and 0.02) ceramics was sintered under an air atmosphere through the solid-state reaction method. The results show that doping with Lu 3+ considerably enhances material permittivity. The ceramic with x = 0.01 exhibits a colossal permittivity (CP) of ∼101000 with a tan δ of ∼0.16 at a frequency of 1 kHz, demonstrating enhanced stability over a wide temperature (30 to 300 °C) and frequency (10 2 to 10 6 Hz) range. Based on the analysis of dielectric relaxation, X-ray photoelectron spectroscopy (XPS), and the universal dielectric response law, the CP effect is primarily due to the formation of defect dipoles, which are correlated with the presence of oxygen vacancies, such as Ti 3+ Ti 3+ , , Ti 3+ , and Ti 3+ . These defect dipoles serve to pin electrons, limiting long-range transitions, and enhancing local polarization. Doping with Lu 3+ also induces a secondary Lu 2 Ti 2 O 7 phase, which are characterized by X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The results generated in this study can inform the development and application of new CP materials based on SrTiO 3 .
研究领域:
材料科学
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固态化学
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电子材料
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2020
·Vol. 10
·期 1
·1-14
·
IF 3.998
Xu JingJing,Fu Chao,Chu Huiying,Wu Xianyou,Tan Zhongyang,Qian Jing,Li Weiyan,Song Zhongqian,Ran Xianghai,Nie Wei
In recent years, high energy density polymer capacitors have attracted a lot of scientific interest due to their potential applications in advanced power systems and electronic devices. Here, core–shell structured TiO 2 @SrTiO 3 @polydamine nanowires (TiO 2 @SrTiO 3 @PDA NWs) were synthesized via a combination of surface conversion reaction and in-situ polymerization method, and then incorporated into the poly(vinylidene fluoride) (PVDF) matrix. Our results showed that a small amount of TiO 2 @SrTiO 3 @PDA NWs can simultaneously enhance the breakdown strength and electric displacement of nanocomposite (NC) films, resulting in improved energy storage capability. The 5 wt% TiO 2 @SrTiO 3 @PDA NWs/PVDF NC demonstrates 1.72 times higher maximum discharge energy density compared to pristine PVDF (10.34 J/cm 3 at 198 MV/m vs. 6.01 J/cm 3 at 170 MV/m). In addition, the NC with 5 wt% TiO 2 @SrTiO 3 @PDA NWs also demonstrates an excellent charge–discharge efficiency (69% at 198 MV/m). Enhanced energy storage performance is due to hierarchical interfacial polarization among their multiple interfaces, the large aspect ratio as well as surface modification of the TiO 2 @SrTiO 3 NWs. The results of this study provide guidelines and a foundation for the preparation of the polymer NCs with an outstanding discharge energy density.
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Microstructures
·
2025
·Vol. 5
·期 1
·N
·
IF 9
Xinjian Li,Xiaohuan Luo,Moran Wang,Tu Lyu,Chaohua Zhang,Fusheng Liu,Hongan Ma,Lipeng Hu
In thermoelectrics, optimizing both carrier and phonon transport is crucial for enhancing thermoelectric performance. Strontium titanate, a representative N-type oxide thermoelectric material, often exhibits inferior figure of merit (zT) due to its large band gap that limits carrier concentration, and high lattice thermal conductivity, attributed to strong Ti-O covalent bonds. Conventional approaches, such as aliovalent doping to increase carrier concentration or introducing structural defects to reduce lattice thermal conductivity, are insufficient as they fail to decouple the interdependent electrical and thermal properties. Herein, we introduce a high-pressure synthesis technique that concurrently modulates both the band gap and microstructure. This approach effectively enhances the carrier concentration by narrowing the band gap and increases the effective mass of the density of states through enhanced solubility limit of rare earth elements, significantly improving the power factor. Additionally, high-pressure condition induces microstructural defects, including point defects, dislocations, lattice distortions, and nanoscale grains, which promote broad-wavelength phonon scattering and minimize lattice thermal conductivity. Consequently, a peak zT value of 0.25 at 973 K is attained in high-entropy (Sr0.2La0.2Nd0.2Sm0.2Eu0.2)TiO3 synthesized at 5 GPa, representing a 5.3-fold improvement over undoped strontium titanate. This work highlights the pivotal role of high-pressure synthesis in decoupling the carrier and phonon transport in thermoelectrics.
研究领域:
材料科学
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凝聚态物理
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Lian Cheng,Kai Liu,Huayun Gao,Zhongming Fan,Naohisa Takesue,Heming Deng,Haibo Zhang,Yongming Hu,Hua Tan,Zilin Yan,Yang Liu
Recent years witness a rapid surge in the research efforts on dielectric capacitors due to their high power density and fast charge/discharge speed. However, the relatively low energy density demands more efforts to meet the lightweight and compact requirement for practical applications. Here, we report sandwich-structured nanocomposite films with strawberry-like Ag@SrTiO 3 nanofillers. The introduction of Ag nanoparticles (NPs) on SrTiO 3 NPs could significantly improve dielectric properties, breakdown strength, energy storage density, and efficiency. As a result, a dramatically enhanced discharged energy density (24.6 J/cm 3 ) and efficiency (86.3%) are reached in sandwich-structured nanocomposite films containing 1.5 wt% Ag@SrTiO 3 nanofillers by the solution casting method. The enhancement of dielectric constant and breakdown strength of nanocomposite films is attributed to the Coulomb-blockade effect of Ag NPs, which inhibits the transformation of electrons. Our finite element simulation explicitly demonstrates that the Coulomb-blockade effect of Ag NPs can effectively improve energy storage performance, which therefore supports the experimental results.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 88
·47615-47624
·
IF 3.708
Ping Li,Chunbo Liu,Guoling Wu,Yang Heng,Shuang Lin,Ao Ren,Kehan Lv,Lisong Xiao,Weidong Shi
In this paper, Fe-doped SrTiO3 (FSTO) photocatalysts were successfully prepared via a facile solvothermal method, and their photocatalytic activities for degrading tetracycline (TC) under visible light irradiation were examined. It was found that doping Fe3+ into the lattice of SrTiO3 resulted in the formation of new absorption bands in the visible light region, and the energy band gap decreased from 3.2 eV to 2.6 eV with Fe3+ doping amounts of 0 to 5 wt%. The photocatalytic experimental results indicated that the as-prepared FSTO photocatalysts generate an extremely high enhancement in the TC degradation ratio compared to the pure SrTiO3 under visible light irradiation. In particular, the FSTO sample doped with 3% Fe exhibited the highest TC degradation ratio (71.6%) in 80 min, which is mainly attributed to the narrowed gap generated by the appropriate level of Fe3+ doping. This work suggests that this doping method should be applicable for exploiting other efficient visible light-driven photocatalysts with wide band gap semiconductors.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CURRENT APPLIED PHYSICS
·
2024
·
IF 2.4
Lujia Cong,Huimin Zhao,Yurui Han,Shan Zhang,Chunyue Gao,Ziwen Cheng,Jiben Yang,Hongbin Wang
Ultraviolet light and short-wavelength blue photons (UV-SWB) can cause damage to the human body under excessive exposure. Strontium titanate (SrTiO 3 ), which is a crucial perovskite oxide with a direct energy band gap of ∼3.2 eV, has great potential for UV-SWB photodetection . In this work, UV-SWB photodetector with high transparency based on Graphene/SrTiO 3 heterojunction was fabricated by graphene transfer method. The Graphene/SrTiO 3 photodetector exhibits an ultra-low dark current of 6 pA at a 30 V bias. The response spectrum of the Graphene/SrTiO 3 photodetector was 220–410 nm, covering the UV-SWB band. Under 385 nm light irradiation, the photodetector exhibits a response of 3.4 mA/W, a detectivity of 1.5 × 10 10 Jones, a response time of 186 ms, and a light-to-dark current ratio of 10 3 magnitude at a 30 V bias. In addition, the transmittance of the photodetector in the visible light band reaches 80 %, which has excellent visualization performance. The excellent performance of Graphene/SrTiO 3 photodetector is attributed to the high crystal quality of SrTiO 3 wafer and the van der Waals interface constructed by Graphene/SrTiO 3 reduces the bulk defect density and interfacial state density, which could be beneficial the separation and transport of photogenerated carriers in the active layer and heterojunction . This study has important reference value for the design and manufacture of UV-SWB photodetectors.
研究领域:
材料科学
·
光电检测
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 34
·9130-9139
·
IF 5.976
Junlei Qi,Minghe Cao,James P. Heath,Julian S. Dean,Hua Hao,Zhonghua Yao,ZhiYong Yu,Hanxing Liu
For single phase dielectric ceramics prepared using a traditional solid state method, the conflict between high dielectric permittivity and low breakdown strength has always limited the improvement of energy storage density. Here, we design a core–shell structure of Sr0.985Ce0.01TiO3 (SCT)@x wt% SiO2 combining a high dielectric permittivity core with an insulating shell material. The sample of x = 3 wt% sintered at 1300 °C has the largest energy storage density ∼2.23 J cm−3. The effects that different amounts of SiO2 have on phase, microstructure, dielectric and energy storage properties were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy with energy dispersive X-ray spectrum (SEM-EDS) and dielectric measurements. As verified by finite element simulations, the energy storage properties are mainly governed by the electric field distribution owing to the introduction of a high dielectric permittivity core (SCT) in a low permittivity shell. The shell material provides an electrical shielding effect around the core, resulting in significant reduction in the field strength within the core material. A comparison of experimental and simulated results is also shown, which is in good agreement with the breakdown properties.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Research Letters
·
2017
·Vol. 12
·期 1
·1-7
·
IF 2.833
Zhao Weijie,Zhang Jing,Pan Jiaqi,Qiu Jianfeng,Niu Jiantao,Li Chaorong
The SrTiO 3 modified rutile TiO 2 composite nanofibers were synthesized by a simple electrospinning technique. The result of XRD, SEM and TEM indicate that the SrTiO 3 /TiO 2 heterojuction has been prepared successfully. Compared with the TiO 2 and SrTiO 3 , the photocatalytic activity of the SrTiO 3 /TiO 2 (rutile) for the degradation of methyl orange exhibits an obvious enhancement under UV illumination. which is almost 2 times than that of bare TiO 2 (rutile) nanofiber. Further, the high crystallinity and photon-generated carrier separation of the SrTiO 3 /TiO 2 heterojuction are considered as the main reason for this enhancement.
研究领域:
材料科学
·
纳米科技
·
光催化
·
环境功能材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Kangchuang Li,Hua Hao,Zhonghua Yao,Minghe Cao,Hanxing Liu
Sr(Nb 0.5 Ga 0.5 ) x Ti 1-x O 3 (x = 1 %, 2 %, 3 %, 5 %) (STNG) ceramics were synthesized in nitrogen atmosphere by a solid state method. All samples exhibited a cubic perovskite structure without secondary phase. With the increase of the co-doped concentration of Nb 5+ and Ga 3+ , the grain sizes increased firstly and then decreased. The STNG ceramic with x = 3 % exhibited a colossal permittivity (CP) of 24502 and a low dielectric loss of 0.012 at 1kHz and room temperature. Compared with those samples sintered in air, the samples sintered in nitrogen atmosphere have a higher dielectric constant with lower dielectric loss. The phase structure, surface morphology, element distribution, element valence states and dielectric properties of STNG ceramics were investigated. And the mechanism of colossal permittivity was also explored, which indicated that the CP could be attributed to the formation of [ T i 4 + • e − V O • • − e • T i 4 + ] defect dipole.
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
危险品化学品经营许可证（带存储）