Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 21
·7535-7544
·
IF 6.1
Hangren Li,Jie Tu,Guoqiang Xi,Xiuqiao Liu,Xudong Liu,Siyuan Du,Dongfei Lu,Da Zu,Yuxuan Zhang,Qingxiao Wang,Dongxing Zheng,Xixiang Zhang,Jianjun Tian,Linxing Zhang
The discovery of ferroelectricity in HfO2-based thin films has strongly energized the field of integrated semiconductor devices. To expand the physical applications of HfO2-based thin films, it is essential to urgently enhance their ferroelectric polarization. In this work, we have synthesized Hf0.85Ce0.15O2−δ thin films with a large remanent polarization of 2Pr ∼ 69 μC cm−2, which is the maximum of all HfO2-based polycrystal thin films. The strong increase of the remanent polarization is caused by the significant lattice expansion triggered by the increase of Ce3+ content, which is controlled by temperature. Due to the increase of the lattice constant in the c-axis, the unit-cell volume expands from 132.16 Å3 to 137.66 Å3, inducing an increase in the distortion of ions along the direction of the polarization axis and leading to an increase in polarization. This finding is of significant practical importance for promoting HfO2-based materials and their development in physical fields.
研究领域:
凝聚态物理
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材料科学
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半导体器件
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功能薄膜
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铁电材料
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yuan Liu,Weiwei Liu,Yang Zhou,Jingbo Chen,Zhiguo Wang,Wen Du,Jianhui Wen,Jun Cao,Dou Zhang
To investigate the influence of modification of ceramic fillers on the dielectric properties of polymer-based composites, TiO 2 and core-shell structured TiO 2 @HfO 2 nanowires were synthesized, and investigated in this study. TiO 2 nanowires/polyvinylidene fluoride (PVDF) and TiO 2 @HfO 2 nanowires/PVDF nanocomposites were prepared using the solution casting method. The experimental results showed that the TiO 2 @HfO 2 nanowires/PVDF composites had improved dielectric properties compared with that of the TiO 2 nanowires/PVDF composites. Owing to the enhanced interfacial polarisation by the multilevel interface, the composites with 10 wt % TiO 2 @HfO 2 nanowires achieved the highest permittivity of 12.56 at 1 kHz, which was enhanced by ∼72% compared to the PVDF matrix. The electric field was evenly distributed by building the fillers with a gradient dielectric constant. The characteristic breakdown strength of the composite with 5 wt % TiO 2 @HfO 2 reached 377.76 kV/mm, compared with that of 334.37 kV/mm for the composite with 5 wt % TiO 2 nanowires. This study initiated a novel strategy for preparing dielectrics with high dielectric constant and improved breakdown strength.
研究领域:
材料科学
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电气工程
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产品关联
DOI
高影响因子
Coatings
·
2022
·Vol. 12
·期 4
·439
·
IF 3.236
Xiangduo Cui,Kamale Tuokedaerhan,Haotian Cai,Zhenchuan Lu
Lanthanum-doped HfO2films were deposited on Si by sol–gel technology. The effects of annealing temperature on the optical properties, interface chemistry, and energy band structure of Lanthanum-doped HfO2films have been investigated. The crystallinity and surface morphologies of the films are strongly dependent on the annealing temperature. X-ray diffraction (XRD) analysis showed a monoclinic phase, and there was a tendency to preferentially grow with increasing temperature. The calculated grain sizes ranged from 17.1 to 22.4 nm on average. It was also confirmed from Raman spectroscopy that increasing the annealing temperature can improve the crystallinity of the films. The surface of the film was smooth, and the film had good interfacial contact with the silicon substrate. The band gap increased from 5.53 to 5.91 eV with increasing annealing temperature. The calculated conduction band offset and valence band offset both exceeded 1 eV. In conclusion, smaller grain size, good crystallinity and interfacial contact can be obtained by adjusting the annealing temperature. Higher conduction band and valence band offsets can meet the minimum barrier height requirements of complementary metal oxide semiconductors (CMOS) and have potential applications.Keywords:high-k gate;sol–gel;thin films;annealing temperature
研究领域:
材料科学
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半导体物理
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Junhui Wang,Jiajia Liao,Tongkun Zhu,Zhipeng Wang,Qiong Yang,Hongze Liu,Shijie Jia,Jin Huang,Sirui Zhang,Jiayi Hu,Jie Jiang,Limei Jiang,Yichun Zhou
Ferroelectric synaptic devices are pivotal in artificial intelligence applications, particularly for image recognition tasks. Their outstanding capabilities in neuromorphic information processing, biologically plausible signal emulation, and faithful neural mimicry render them indispensable. However, for HfO 2 -based ferroelectric synaptic devices, concurrently attaining high remnant polarization and rapid domain switching which are essential for high-speed processing and precise pattern recognition remains a formidable challenge. In this study, gradient Zn-doped HfCeO x (Zn: HCO) ferroelectric film was fabricated. It displays enhanced ferroelectric properties with a remnant polarization (2 P r ) reaching 77.2 µC/cm 2 . High-resolution transmission electron microscopy analyzes and phase-field simulations reveal that the gradient Zn doping induces a flexoelectric effect in HfCeO x thin films, which promotes the formation of the ferroelectric orthorhombic phase. Additionally, this gradient design accelerates domain switching speed by enhancing the domain wall mobility under applied electric fields. To demonstrate the neuromorphic computing potential, we implemented an artificial neural network using Pt/Zn: HCO/p + -Si synaptic devices, achieving an 86.5 % recognition accuracy in standard pattern classification tasks. This work establishes a viable strategy for simultaneously enhancing both ferroelectric polarization and switching speed in HfO 2 -based memory and neuromorphic devices.
研究领域:
材料科学
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微电子学
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纳米科技
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神经形态工程
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固态物理
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产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2024
·
IF 9
Xian Shi,Xinyi Xing,Wanni Liu,Mengya Ruan,Ying Guan,Gaojin Lyu,Hui Gao,Siquan Xu
The efficient catalytic conversion of cellulose to 5-hydroxymethylfurfural (HMF) can provide a valuable reference for the high-value utilization of biomass. In this work, a series of simple phosphate-doped hafnium oxide catalysts (x-P-HfO 2 ) were prepared, and their physicochemical properties were analyzed by ICP-OES, XRD, XPS, FTIR, SEM-EDX, N 2 adsorption-desorption isotherms, NH 3 -TPD and Py-FTIR characterizes. Detailed evaluation of the reaction conditions demonstrated the ideal catalytic performance of the x-P-HfO 2 catalysts, and the HMF yield from cellulose reached a satisfactory 61% in the water (NaCl) /tetrahydrofuran biphasic reaction system. Based on the captured intermediates and detected by-products, possible catalytic pathways are summarized. Meanwhile, the hydrothermal stability of the catalyst was also investigated, and the reason for its performance degradation after five cycles was determined to be the loss of useful Brønsted active sites. In addition, the effects of the phosphating and sulfating modification approaches on the catalyst activity were also compared, verifying that the introduction of phosphate is more conducive to the catalyst expressing high activity for the formation of HMF from cellulose.
研究领域:
催化
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生物质转化
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材料科学
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化学工程
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产品关联
DOI
高影响因子
Advanced Healthcare Materials
·
2024
·
IF 10
Zede Wu,Qiuyu Li,Kai Zhu,Shuting Zheng,Honglei Hu,Meirong Hou,Li Qi,Siwen Chen,Yikai Xu,Bingxia Zhao,Chenggong Yan
Immunotherapy has emerged as an innovative strategy with the potential to improve outcomes in cancer patients. Recent evidence indicates that radiation-induced DNA damage can activate the cyclic-GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway to enhance the antitumor immune response. Even so, only a small fraction of patients currently benefits from radioimmunotherapy due to the radioresistance and the inadequate activation of the cGAS-STING pathway. Herein, this work integrates hafnium oxide (HfO 2 ) nanoparticles (radiosensitizer) and 7-Ethyl-10-hydroxycamptothecin (SN38, chemotherapy drug, STING agonist) into a polydopamine (PDA)-coated core-shell nanoplatform (HfO 2 @PDA/Fe/SN38) to achieve synergistic chemoradiotherapy and immunotherapy. The co-delivery of HfO 2 /SN38 greatly enhances radiotherapy efficacy by effectively activating the cGAS-STING pathway, which then triggers dendritic cells maturation and CD8 + T cells recruitment. Consequently, the growth of both primary and abscopal tumors in tumor-bearing mice is efficiently inhibited. Moreover, the HfO 2 @PDA/Fe/SN38 complexes exhibit favorable magnetic resonance imaging (MRI)/photoacoustic (PA) bimodal molecular imaging properties. In summary, these developed multifunctional complexes have the potential to intensify immune activation to realize simultaneous cancer Radio/Chemo/Immunotherapy for clinical translation.
研究领域:
癌症研究
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纳米技术
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免疫治疗
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放射肿瘤学
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分子成像
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药物递送系统
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Chun Li,Jiaxun Yao,Jiayi Xu,Huanhuan Yang,Guangfu Luo,Yanhao Yu
Nucleation behavior governs the selectivity of area-selective atomic layer deposition (AS-ALD). Ideally, nontargeted regions should exhibit delayed nucleation or sparse nucleation that can be easily removed by post-treatment. Here, we report a burst nucleation phenomenon during AS-ALD on perfluoroalkyl self-assembled monolayer (SAM)-treated surfaces. Burst nucleation results in discontinuous particle deposition with weak interfacial adhesion on nontargeted regions, in contrast to the progressive nucleation that forms uniform and adherent films on alkyl SAMs. These weakly adhered particles can be completely removed by gentle wiping without affecting the ALD film in targeted areas. The burst window depends on the SAM chain length, the ALD precursor, and the ALD temperature. When applied to Cu/SiO2 substrates, the nucleation control enables 99.9% selectivity after 30 cycles of Al2O3 ALD, while that of alkyl SAMs is 52.2%. The burst nucleation strategy is broadly effective for enhancing the selectivity of AS-ALD oxides (e.g., ZrO2, HfO2, ZnO) and polymers (e.g., polyimide).
研究领域:
材料科学
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纳米技术
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薄膜沉积
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表面化学
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半导体工艺
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOBIOTECHNOLOGY
·
2024
·Vol. 22
·期 1
·1-16
·
IF 10.6
Hu Honglei,Zheng Shuting,He Chenxi,Zheng Yinfei,Wei Qiming,Chen Siwen,Wu Zede,Xu Yikai,Zhao Bingxia,Yan Chenggong
Radiotherapy-induced immune activation holds great promise for optimizing cancer treatment efficacy. Here, we describe a clinically used radiosensitizer hafnium oxide (HfO2) that was core coated with a MnO2 shell followed by a glucose oxidase (GOx) doping nanoplatform (HfO2@MnO2@GOx, HMG) to trigger ferroptosis adjuvant effects by glutathione depletion and reactive oxygen species production. This ferroptosis cascade potentiation further sensitized radiotherapy by enhancing DNA damage in 4T1 breast cancer tumor cells. The combination of HMG nanoparticles and radiotherapy effectively activated the damaged DNA and Mn2+-mediated cGAS-STING immune pathway in vitro and in vivo. This process had significant inhibitory effects on cancer progression and initiating an anticancer systemic immune response to prevent distant tumor recurrence and achieve long-lasting tumor suppression of both primary and distant tumors. Furthermore, the as-prepared HMG nanoparticles “turned on” spectral computed tomography (CT)/magnetic resonance dual-modality imaging signals, and demonstrated favorable contrast enhancement capabilities activated by under the GSH tumor microenvironment. This result highlighted the potential of nanoparticles as a theranostic nanoplatform for achieving molecular imaging guided tumor radiotherapy sensitization induced by synergistic immunotherapy.
研究领域:
癌症研究
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放射肿瘤学
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免疫治疗
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纳米技术
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分子影像学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2022
·Vol. 105
·期 12
·7726-7740
·
IF 4.186
Xuemeng Zhang,Jia Sun,Yuyu Zhang,Hejun Li
The SiHfOC ceramic microspheres were synthesized from the polysilazane and hafnium(IV) acetylacetonate hybrid precursors through a combination of hydrothermal method and polymer-derived ceramics (PDCs) method. The SiHfOC ceramic microspheres consist of β-SiC, SiO 2 , and m -HfO 2 in an amorphous SiOC matrix and are in a spherical morphology with an average size of about 2 μm. Hafnium-containing nanoparticles with ∼50-nm size are not only uniformly distributed on the surface of the ceramic microspheres but also embedded in the SiHfOC ceramic microspheres, forming a unique mosaic structure. Pyrolyzing at 1000°C offers a possibility of an in situ formation of nanocrystal nuclei in the amorphous SiOC ceramic matrix, and the subsequent annealing at 1500°C helps the small nanocrystal nuclei grow and separate the amorphous SiHfOC into a multiphase SiOC network containing β-SiC, SiO 2 , m -HfO 2 nanocrystalline and free C. This research provides a methodology for preparing multicomponent ceramic microspheres that can efficiently develop high-performance PDCs modified by transition metal alkoxide.
研究领域:
材料科学
·
陶瓷
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Xi Wu,Fei Ruan,Fenglong Zhang,Zhe Ren,Chonggui Lei,Yuwei Ma,Gaofei Pan,Weixiang Shang,Hongxia Li,Qingchun Wang,Jinxiao Bao
To study the electrochemical performance of aluminum doped CaHfO 3 proton conductors in more detail, the CaHf 1- x Al x O 3-δ ( x = 0.02,0.04,0.06,0.08) solid electrolytes were prepared by high-temperature solid-state method at the temperature of 1873K for 10 h. The XRD, SEM and EDS were used to test the phase structure and micro-morphology of the solid electrolytes, the Archimedes method was used to measure the density of the electrolytes, and the electrochemical workstation was used to test the performance of the electrolytes. The conductivity of the electrolytes in hydrogen, oxygen and water vapor atmospheres at 973–1373 K were measured by two-electrode AC impedance spectroscopy method, and the conductance activation energy of the electrolytes in different atmospheres were estimated based on Arrhenius' law. The H/D isotope effect of solid electrolytes were measured at 973–1273 K in H 2 and D 2 atmospheres, and the chemical diffusion coefficient and self-diffusion coefficient of hydrogen in the electrolytes were determined based on Fick's second law. The primary conducting carriers in different temperatures and atmospheres were revealed based on the conductivity test results. This study of aluminum-doped calcium hafnate electrolyte may provide reference for the research and development of calcium hafnate based proton conductors.
研究领域:
材料科学
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电化学
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固体物理
·
能源材料
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Wuyang Song,Youjun Lu,Chuyun Wang,Jiahao Xu,Xiang Liu,Bo Ma,Yanmin Wang,Bo Wu
The cell structures and mechanical properties (i.e., hardness, Young's modulus , shear modulus , and Poisson's ratio) of (Hf 0.2 Zr 0.2 Ti 0.2 Nb 0.2 Ta 0.2 )C (HEC) and (Hf 0.2 Zr 0.2 Ti 0.2 Nb 0.2 Ta 0.2 )N (HEN) high-entropy ceramics were simulated by special quasi-random structure (SQS) and general random structure (GRS) with atomic occupation preference based on the first-principles density functional theory. The results show that compared to SQS, the cell structure constructed by GRS is more realistic, which is verified via scanning electron microscopy, high resolution transmission electron microscopy and energy dispersive spectroscopy. The mechanical properties simulated by GRS were also determined by microhardness and dynamic elastic modulus testers. The hardness, Young's modulus，shear modulus and Poisson's ratio predicted by GRS are 23.07 GPa, 449.71 GPa, 183.28 and 0.227 for HEC and 22.96 GPa, 413.71 GPa, 162.47 and 0.241 for HEN, which are in a reasonable agreement with the measured results (i.e., 22.05 ± 0.32 GPa, 433 ± 12 GPa, 172 ± 18 GPa, 0.21 for HEC and 22.12 ± 0.13 GPa, 372 ± 23 GPa, 158 ± 11 GPa, 0.23 for HEN). This work can provide a promising reference for preparing high-entropy non-oxide ceramics via the prediction.
研究领域:
材料科学
·
计算材料学
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产品关联
DOI
高影响因子
Materials Today Chemistry
·
2024
·
IF 6.7
Jingming Chan,Balaji Devakumar,Huanzhuo Gao,Xiaoyong Huang
High-color-rendering full-spectrum warm-white light-emitting diodes (LEDs) are in great demand in the field of high-end solid-state white lighting. However, the so-called cyan gap (480–520 nm) in conventional white LEDs always limits their color rendering index (CRI) values, and thus there is a pressing need for cyan phosphors to fabricate full-spectrum white LEDs. Herein, we report on an efficient violet-excited blue-cyan-emitting Ca 2 YHf 2 GaAl 2 O 12 :Ce 3+ (CYHGA:Ce 3+ ) garnet phosphor, which is capable of realizing full-spectrum warm-white LEDs with superior CRI (Ra = 98.2, R12 = 96, R9 = 95) and low correlated color temperature (CCT) of 3735 K. Importantly, when excited at 398 nm, the optimal CYHGA:2%Ce 3+ sample exhibits a strong broadband blue-cyan emission (emission peak: 473 nm; emission bandwidth: 92 nm) with high luminescence efficiency (internal quantum efficiency: 69.9 %; external quantum efficiency: 43.3 %), which perfectly covers both blue and cyan spectral region and enables to close the so-called cyan gap. The fabricated warm-white LED device based on CYHGA:2%Ce 3+ blue-cyan phosphor generates bright warm-white lights with ultra-high CRI values (Ra ≥96.5; R12 ≥ 94; R9 ≥ 93) and low CCT values (3674–3845 K) upon 20–320 mA driving currents. Thus, blue-cyan-emitting CYHGA:Ce 3+ garnet phosphors possess a bright application prospect in high-quality full-spectrum LED lighting.
研究领域:
材料科学
·
光学工程
·
固态照明
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）