Crystals
·
2022
·Vol. 12
·期 3
·405
·
IF 2.67
Yun Liu,Binbin Huang,Xiaoyang Chen,Ping Yu
Mg2TiO4-doped Ca0.65Sr0.35Zr0.65Ti0.35O3(CSZT) thin films with different Mg2TiO4concentrations were deposited on the LaNiO3(LNO)/p-Si substrate using radio-frequency magnetron sputtering technology. The dielectric response of the prepared x% Mg2TiO4-CSZT thin films with frequency, voltage, and temperature was systematically studied. The tanδ and leakage current density of CSZT thin films were reduced effectively by introducing Mg2TiO4content. The prepared 6% Mg2TiO4-CSZT thin film, due to its low loss (tanδ ~0.01 at 1 MHz), satisfied temperature stability (TCC ~−68 ppm/°C, from −55 °C to 205 °C), high withstand voltage (>160 V), and small leakage current density (about 3.34 × 10−6A/cm2at operating voltage of 160 V). This may be useful for capacitor materials in the next generation of portable electronic systems.Keywords:linear dielectric thin films;RF magnetron sputtering
研究领域:
材料科学
·
电子工程
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DOI
高影响因子
Additive Manufacturing
·
2023
·
IF 11
Fei Liu,Hanwei He,Lijin Cheng,Hao Li,Mohsen Abdel-Naeim Hassan Mohamed,Ning Hu,Shaojun Liu
Temperature-field-assisted vat photopolymerization has been applied to prepare Mg 2 TiO 4 ceramics with few defects and remarkably reduced dielectric loss . These excellent properties could be attributed to the significantly reduced viscosity and increased curing depth of the prepared ceramic slurry with a high solid loading when the photopolymerization temperature reaches 65 °С. Increasing the temperature helped to increase the kinetic energy of the resin molecules and reduce the viscosity of the ceramic slurry. This ensured a smooth spreading of the slurry and suppressed the formation of intra-layer defects during the printing process. Additionally, increasing the curing temperature enhanced the activation energy of the free radicals and accelerated the transfer of molecular chains , thereby increasing the polymerization rate and curing depth of the slurry. This reduced the interlayer pores of the Mg 2 TiO 4 green bodies. Thus, Mg 2 TiO 4 ceramic slurry with a high solid loading could be successfully printed by applying a temperature field. Significantly fewer defects were found in Mg 2 TiO 4 ceramics printed with 57.5 vol% solid loading than those in the samples printed with 50 vol% solid loading. The quality factor of Mg 2 TiO 4 ceramics sintered at 1550 °С for 4 h using ceramic slurries with 57.5 vol% solid loading could reach 150,000 GHz when printed at a curing temperature of 65 °С, this value is equivalent to that of dry-pressed ceramics.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Shufang Chang,Yiwen Hu,Jun Qian,Yinlin Shao,Shuang Ni,Lulu Kong,Wenyan Dan,Chun Luo,Shu Jin,Xiaoxiang Xu
Nitrogen doped Mg 2 TiO 4 spinel, i.e. Mg 2 TiO 4−x N y , has been synthesized and investigated as a photocatalyst for antibacterial activity. Mg 2 TiO 4−x N y demonstrates superior photocatalytic activity for E. coli disinfection under visible light illumination (λ ≥ 400 nm). Complete disinfection of E. coli at a bacterial cell density of 1.0 × 10 7 CFU mL −1 can be achieved within merely 60 min. Mg 2 TiO 4−x N y is capable of generating superoxide radicals ( O 2 − ) under visible light illumination which are the reactive oxygen species (ROSs) for bacteria disinfection. DFT calculations have verified the importance of nitrogen dopants in improving the visible light sensitivity of Mg 2 TiO 4−x N y . The facile synthesis, low cost, good biocompatibility and high disinfection activity of Mg 2 TiO 4−x N y warrant promising applications in the field of water purification and antibacterial products.
研究领域:
材料科学
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环境科学
·
微生物学
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光催化
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纳米医学
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生物材料
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DOI
高影响因子
Journal of Advanced Ceramics
·
2020
·Vol. 10
·期 1
·88-97
·
IF 2.889
Wang Zixin,Lin Hui,Zhang Dawei,Shen Yiming,Li Yang,Hong Ruijin,Tao Chunxian,Han Zhaoxia,Chen Lei,Zhou Shengming
In this study, deep-red emitting Mg 2 TiO 4 :Mn 4+ phosphor ceramics were synthesized by the high temperature solid-state reaction method. The ceramics can be excited by the 465 nm blue light and had a narrow emission with a full width at half maximum (FWMH) value of 31 nm. The peak wavelength was located at 658 nm, which matched the demanded wavelength for photosynthesis. The crystal field strength ( D q ) and the Racah parameters ( B and C ) were estimated by the Tanabe-Sugano diagram. The thermal conductivity of the Mg 2 Ti( 0.999 )O 4 :0.001Mn 4+ ceramic was 7.535 W/(m·K) at room temperature, which was one order of magnitude higher than that of the traditional packaging method using the silicone gel. A set of phosphor converted LEDs were fabricated by mounting the phosphor ceramics onto the 460 nm blue LED chips and the CIE coordinates can move from the blue region to the purple light region with the thickness of the ceramic increasing. These results indicated that the Mg 2 TiO 4 :Mn 4+ phosphor ceramic was suitable for plant lighting when combined with a blue LED chip.
研究领域:
材料科学
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光电技术
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农业工程
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Lijin Cheng,Pengxiang Hao,Fei Liu,Yan Li,Yujie Zhao,Shaojun Liu
The (1-x)Mg 2 TiO 4 -xCa 0.8 Sr 0.2 TiO 3 (MT-CST) ceramic filters with intricate structures, low insertion loss and near-zero resonant frequency temperature coefficient were successfully fabricated by heated-assisted digital light processing (DLP). The excellent dielectric properties of DLP-printed ceramic filters could be attributed to the utilization of ceramic slurries with high solid loading, the improvement of forming accuracy and the control of CST content. The increasing of curing temperature could facilitate the mobility of the molecular segments and increase the activation energy of the free radicals, consequently leading to the reduction in viscosity and the improvement in curing properties of the MT-CST ceramic slurries with 57.5 vol% solid loading. The forming accuracy was regulated by fine-tuning the exposure energy densities. The excess curing width of precision model increased from 25 to 35 μm when the exposure energy densities increased from 7 to 11 mJ/cm 2 . The 0.91MT-0.09CST ceramics sintered at 1450 ℃ for 4 h exhibited excellent dielectric properties: ε γ = 17.5; Q × f = 46,800 GHz; τ f = -3.21 ppm/℃. The DLP-printed 0.91MT-0.09CST ceramic filters showed an excellent insertion loss of −1.3 dB.
研究领域:
材料科学
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电子陶瓷
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功能材料
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先进制造
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微波器件
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产品关联
DOI
高影响因子
Solids
·
2025
·Vol. 6
·期 3
·53
·
IF 2.4
Chenxing Liao,Huihuang Cai,Dongyuan Dai,Liaolin Zhang
Mg2TiO4:Mn4+(MTO:Mn4+) red phosphor has important applications in areas such as red LEDs and forensic science, but the preparation of MTO:Mn4+through the solid-state reaction method requires a high sintering temperature. Herein, MTO:Mn4+red phosphor was synthesized using the solid-state reaction method with LiCl flux, and its crystallographic structure and photoluminescence properties were studied to determine the influence of experimental parameters like the amount of fluxing agent added and sintering temperature in producing a bright red phosphor suitable for LEDs. The experimental results showed that samples with added LiCl could form pure MTO after sintering at 950 °C, whereas those without LiCl still contained a mixture of MTO and MgTiO3, even when sintered at 1400 °C. The optimal performance was achieved with a sample doped with 0.2 mol% Mn4+, synthesized using 50 wt% LiCl flux and sintered at 950 °C for 12 h. This sample exhibited a broad excitation band and a narrow red emission band peaking at 662 nm, confirming its excellent luminescence properties. Furthermore, a prototype red LED fabricated with a 377 nm chip and MTO:0.2% Mn4+phosphor achieved photoelectric conversion efficiency of 78.5% at a 100 mA drive current, confirming its viability for high-performance red LED manufacturing.
研究领域:
材料科学
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发光材料
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无机化学
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固体化学
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光电子学
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产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Zhiwei Wang,Qiuying Wang,Yi Wang,Theeranun Siritanon,M.A. Subramanian,Peng Jiang
Mg 2.2- x Co x TiO 4 (0 ≤ x ≤ 0.6) and Mg 2.2- x Cr x TiO 4 (0 ≤ x ≤ 0.6) solid solutions with spinel structure were successfully synthesized by solid-phase reaction. Excess MgO was added to achieve the single phase of the compounds. The transition metal ions Co/Cr tune the colors of Mg 2 TiO 4 to intense blue and green, respectively. The root of the observed intense blue color of Mg 2.2- x Co x TiO 4 is attributed to the 4 A 2 (F) → 4 T 1 (P) transition of Co 2+ in tetrahedral coordination. In Cr doped Mg 2 TiO 4 , Cr exists in a mixed oxidation states of +3 and + 6. The green color of the as-synthesized Mg 2.2- x Cr x TiO 4 is attributed to 4 A 2 (F) → 4 T 1 (F) at 410 nm–500 nm and 4 A 2 (F) → 4 T 2 (F) at 610 nm transitions of Cr 3+ . Besides, the Cr 3+ - Ti 4+ charge-transfer transition at 410 nm–500 nm is also the reason why it shows green. The as-synthesized pigments were dispersed into PMMA to prepare blue/green plastics.
研究领域:
材料科学
·
无机化学
·
颜料技术
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 48
·期 24
·36638-36643
·
IF 5.532
Fu Zhifen,Xiangyang Chen,Zhongyi Yang,Simei Zhai
The Mg 2 TiO 4 - x wt% LiF–2CaF 2 –2B 2 O 3 (LCB, 3.0 ≤ x ≤ 10.0) ceramics were fabricated to study the relationship among LCB additive and the sintering behavior, phase composition, micro-structure and dielectric performance of ceramics in this study. The sintered ceramics are mainly Mg 2 TiO 4 phase, accompanied by small amount of second phase CaTiO 3 and Mg 3 B 2 O 6 . They are generated from the chemical reaction of CaF 2 and B 2 O 3 with the matrix material, respectively. Appropriate LCB additive significantly enhanced sintering ability and dielectric performance of Mg 2 TiO 4 -based ceramics. Sintered at 1175 °C, Mg 2 TiO 4 -7.5 wt% LCB ceramics exhibited a dielectric performance: ε r of 15.3, Q × f of 32 950 GHz and τ f of +1.96 ppm/°C, which is expected to be an alternative material for communication component.
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Shuai Ma,Xiaohua Zhang,Jie Zhang,Xiaohui Zhang,Yu Liu,Chenglong Yu,Zhenxing Yue
Low-loss microwave dielectrics are of significant importance for the miniaturization and integration of microwave devices. In this paper, the ceramics of nominal composition Mgn+1TinO3n+1 (n = 3–6) are synthesized, and the correlations among their phase compositions, defect behaviors, and microwave dielectric properties are systematically investigated. The analyses indicate that the Mgn+1TinO3n+1 ceramics are a biphasic system consisting of hexagonal ilmenite-structured MgTiO3 and cubic spinel-structured Mg2TiO4. The Rietveld refinement results demonstrate that as the n value increases, the content of the MgTiO3 phase gradually increases, while that of the Mg2TiO4 phase decreases. The results of the thermally stimulated depolarization current (TSDC) indicate that the oxygen vacancy-related defects are considered to be the main types of defects in Mgn+1TinO3n+1. As the value of n increases, the increase of the MgTiO3 phases with a more stable crystal structure leads to a gradual decrease in the concentration of oxygen vacancies. The Mgn+1TinO3n+1 ceramics exhibit excellent microwave dielectric properties at n = 6: εr = 17.55, Q × f = 284,600 GHz, and τf = −46.39 ppm/°C. In addition, the relationship between the dielectric constant and the electric field distribution is solved utilizing high-frequency structure simulator (HFSS) software, and the Q × f values are also predicted. The low-frequency dielectric temperature spectra and direct current pulse charge/discharge tests show that the low-loss Mgn+1TinO3n+1 ceramics can be good candidates for microwave capacitors even when operated under high-temperature conditions.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 13
·1-8
·
IF 2.8
Cai Chenxi,Tao Zhenli,Zuo Jianan
Within the scope of this research, Li 2 Mg 6 TiO 9 -based ceramics were prepared by a traditional solid-state sintering technique. The research analyzed the influence of lithium (Li) volatilization during the sintering process, on the phase composition, and resultant microwave dielectric performances (MIDP) of the Li 2 Mg 6 TiO 9 -based ceramics, employing advanced analytical techniques. X-ray diffraction and Raman spectroscopy analyses indicated the emergence of a second phase Mg 2 TiO 4 within the sample when the sintering temperature attained 1550 °C due to Li volatilization. The generated Mg 2 TiO 4 could effectively tune the MIDP of the ceramics. Optimal MIDP of Li 2 Mg 6 TiO 9 -based ceramics were derived from a sintering temperature of 1650 °C: dielectric constant ( ε r ) = 12.78, quality factor ( Q × f ) = 129,010 GHz, temperature coefficient of resonant frequency ( τ f ) = − 46.2 ppm/°C. Low ε r and ultrahigh Q × f indicate that the current ceramics have potential application prospects in millimeter wave communication as substrate materials.
研究领域:
材料科学
·
陶瓷工程
·
电子材料
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Fei Liu,Hao Li,Yujie Zhao,Jiarui Huang,Lijin Cheng,Xianfeng Yang,Shaojun Liu
This study presents a novel approach for fabricating multi-frequency microwave devices through structural engineering of Mg 2 TiO 4 ceramics. Utilizing digital light processing (DLP) technology, we successfully fabricate triply periodic minimal surface (TPMS) structures with precisely controlled porosity ranging from 40 to 60 %. Microstructural characterization via SEM and X-CT reveals uniform, dense ceramics with designed porosity gradients and no observable cracks. The dielectric properties demonstrate significant tunability, with the Q × f values decreasing from 118,000 to 57,800 GHz and the dielectric constant reducing from 8.85 to 5.49 as porosity increasing. Correspondingly, the center operating frequency of Mg 2 TiO 4 based dielectric resonator antennas (DRAs) shifts from 6.53 to 8.18 GHz, while the operational bandwidth substantially expands from 472 to 1063 MHz. Excellent agreement between simulated and measured reflection paramter ( S 11 ) validates the design methodology. These findings establish porosity engineering via DLP as a viable strategy for developing multi-band microwave devices with tailored dielectric properties.
研究领域:
材料科学
·
陶瓷工程
·
微波技术
·
增材制造
·
电磁器件
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2016
·
IF 2.435
Jiaqi Long,Chaoyang Ma,Yuzhen Wang,Xuanyi Yuan,Miaomiao Du,Ran Ma,Zicheng Wen,Jiantao Zhang,Yongge Cao
TiO 2−x MgO: 0.1 at% Mn 4+ (1 ≤ x ≤ 2) red phosphors are synthesized through a traditional high temperature solid-state reaction method. The excitation and emission spectra indicate that 700 nm and 660 nm red emission peaks are ascribed to Mn 4+ ions doped in MgTiO 3 and Mg 2 TiO 4 , respectively. The Ti 4+ octahedron is connected in MgTiO 3 by O 2− ions of the octahedrons, while the Ti 4+ octahedron is separated in Mg 2 TiO 4 by Mg 2+ tetrahedron and Mg 2+ octahedron. This results that the quenching concentration is higher in Mg 2 TiO 4 than in MgTiO 3 leading the less luminous centers in MgTiO 3 . Detailed spectroscopic and crystal-field studies of the Mg 2 TiO 4 : Mn 4+ and MgTiO 3 : Mn 4+ is described in the present paper.
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DOI
高影响因子
危险品化学品经营许可证（带存储）