JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 22
·20277-20284
·
IF 2.22
Wu Xiao-Hui,Tao Zheng-Xiong,Li Le-Zhong,Wu Chong-Sheng,Zhong Xiao-Xi,Wang Rui,Xiang Peng-Cheng,Li Ke-Lin,Lin Nan
In this work, Ni 0.7− x Zn 0.3 Co x Fe 2 O 4 ( x = 0, 0.05, 0.10, 0.15 and 0.20, NZCF) ferrites were successfully fabricated by solid-state reaction method. We have been more focused on the effects of cobalt-substituted NiZn ferrite on crystal structure, microstructure and magneto-electric properties. With gradual addition of cobalt content, since the smaller ionic radius and larger atomic weight of the cobalt, which leads to decrease lattice parameter ( a ) and enhance X-ray density ( d x ), respectively. The grain size ( D ) increases (4.86 ± 1.10 to 6.26 ± 1.67 μm). When x = 0.05, the initial permeability ( μ i ) of NiZnCo ferrites reaches the maximum value. The saturation magnetization ( M s) is firstly decreased slightly from 78.96 to 77.96 emu/g when x ≤ 0.10, then increased to 83.14 emu/g ( x = 0.15), ultimately decreased to 81.54 emu/g. Meanwhile, the coercivity ( H c) is dropped from 19.95 to 13.25 Oe when x ≤ 0.05, and stabilized at about 13.40 Oe when x > 0.05. From the dielectric spectrum, the real dielectric constant (ε′) exhibits typical relaxation-dispersion behavior with increasing frequency. The resistivity temperature spectrum also shows good performance: both dc resistivity ( ρ ) and activation energy ( E ρ ) increase with the Co substitution. Here, we have developed a NiZnCo ferrite when Co-substituted x = 0.05 with the highest permeability ( μ i , 123@10 kHz), higher saturation magnetization ( M s, 78.25 emu/g) and lowest coercivity ( H c, 13.25Oe), which is expected to be used in high-frequency capacitors and inductors.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Fei Xie,Yang Chen,Minyu Bai,Pinglu Wang
In the present work, a Co-substituted LiZnTiBi (Li 0.43 Zn 0.27 Co x Ti 0.13 Fe 2.167-x Bi 0.003 O 4 ) ferrite with equivalent permeability and permittivity was prepared by a low-temperature sintering method. In detail, the LiZnTiBi ferrite with high permeability was obtained by a solid phase method. Next, different mass of Co 2 O 3 (x = 0.100, 0.125, 0.150, 0.175 and 0.200) were added to reduce permeability ( μ r ’ ) and enhance cut-off frequency ( f r ) of the ferrite. Results indicated that the Co-substituted LiZnTiBi ferrite with equivalent permeability and permittivity ( μ r ’ = ε r ’ = ∼12.3) was obtained when additive amount of Co 2 O 3 (x) is around 0.150. Meanwhile, the cut-off frequency ( f r ) of the ferrite is more than 500 MHz. Also, the influences of Co 2 O 3 additive on the microstructure and phase structure of the LiZnTiBi ferrite have been investigated and discussed. SEM images indicated that the Co-substituted LiZnTiBi ferrites possess uniform and compact grains (average grain size is ∼1 μm). XRD patterns demonstrated that the LiZnTiBi ferrite material has a pure spinel structure. Rietveld refinement of XRD proved that Fe 3+ is substituted by Co 3+ . And energy dispersive spectrometer (EDS) result indicated that the Co element is existed in ferrite grains. Such a low-temperature sintering ferrite substrate material with equivalent permeability and permittivity at high frequency (@500 MHz) should also be an alternative material for microwave devices, especially for miniature antenna.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
H.L. Pan,L. Cheng,H.T. Wu
Li 2 (Mg 1−x Co x ) 3 TiO 6 (x = 0, 0.1, 0.2, 0.3, 0.4) ceramics were prepared using the conventional solid-state reaction method. Effects of Co-substitution on the crystal structure, sintering characteristics, micro–structures, microwave dielectric properties and Raman spectra were investigated. Co-substitution would affect the crystal structure and further influence the microwave dielectric properties. On the basis of the chemical bond theory and Rietveld refinement , some intrinsic factors such as the lattice energy, bond ionicity were calculated to explain the variations of the microwave dielectric properties. Ti–O and Li–O bonds played major role in influencing intrinsic factors and correlations between intrinsic factors of Ti–O, and Li–O bonds and microwave dielectric properties were established. With the increase of x values, the dielectric constant ( ε r ) gradually increased, which could be explained by the variations of the polarizability, bond ionicity of Ti–O bonds, and Raman vibration modes. The decrease of the quality factor ( Q·f ) could be predicted by the decrease of the bond valence, packing fraction and lattice energy of Ti–O bonds. The temperature coefficient of resonant frequency ( τ ƒ ) significantly correlated with the bond energy of Li–O bonds and thermal expansion coefficient of Ti–O bonds.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Xiang Wang,Haoran Wang,Min Li,Qingtao Guo,Ben Ge,Xingyu Xiong,Zhibin Yang
This work focuses on the development of high-performance La 0.1 Sr 1.9 TiFeO 6-δ (LSTF)-based fuel electrode materials through targeted Co substitution at the Ti site and Fe site. By selectively substituting Ti or Fe with Co element, lattice contraction and change of the Fe 3 ⁺/Fe 4 ⁺ ratio in LSTF double perovskite are achieved. La 0.1 Sr 1.9 Ti 0.8 Co 0.2 FeO 6-δ (LSTCF) material obtains higher oxygen vacancy concentration and better CO 2 adsorption capacity. Electrochemical impedance spectroscopy (EIS) test demonstrates that the La 0.1 Sr 1.9 TiFe 0.8 Co 0.2 O 6-δ (LSTFC) electrode exhibits superior performance in gas transport process, while the LSTCF electrode demonstrates significant advantages in oxygen ion conductivity and dissociative adsorption of CO 2 species. The single cell with the LSTCF electrode exhibits superior electrolysis performance, achieving a current density of 1.07 A·cm −2 at 800 °C and 1.8 V for CO 2 electrolysis. This work provides a novel pathway for the development of catalysts for solid oxide electrolysis cell (SOEC) fuel electrodes.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Pan Yang,Qingcui Liu,Feng Yu,Jianning Wu,Zhiyong Liu,Banghua Peng
Hydrogen production from photoelectrocatalytic (PEC) water splitting is an emerging technology that can convert and store solar energy into chemical fuels quickly and efficiently. Although many materials with excellent PEC properties have emerged, the endeavor of exploring new substances to improve PEC efficiency has never stopped. Herein, TiO 2 nanorods (NRs) are modified with cobalt substituted polyoxometallate (denoted as Co-POMs), and it is verified that the introduction of Co-POMs accelerated the efficiency of charge separation and migration, retarded the electron-hole recombination and enhanced the light absorption capability of photoanode, thus significantly boosted the PEC performance of Co-POMs/TiO 2 NRs compared with the pristine TiO 2 . This work develops a new TiO 2 -based composite material and expands the utility of POMs in solar energy conversion field to further improve the PEC performance in hydrogen energy production process.
研究领域:
材料科学
·
能源转换技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Muhammad Kashif Naseem,Mian Azmat,Changliang Du,Muhammad Ismail,Hajra Baig,Rong Jiang,Asif Ali,Meishuai Zou,Youqi Zhu,Chuanbao Cao
Vanadium tetrasulfide (VS4) is one of the most promising cathodic materials for rechargeable magnesium battery systems (RMBSs). Elemental substitution to expand layers, creation of sulfur vacancies, and reduction of particle sizes of VS4 are undoubtedly effective strategies to enhance cathodic performances. Experimental and DFT analysis revealed that valence states of vanadium and cobalt have been elevated from V2+ to V3+ and Co2+ to Co3+ in VS4 and that the Co–S bond length shortened due to cobalt substitution, which resulted in enhanced overall internal polarization in the layered atomic structure of VS4 by increasing cobalt concentrations. This phenomenon of charge accumulation contributes toward regulated magnesiation and accommodated volume expansion while cycling, resulting in the enormous structural stability of VS4 and sustainable battery performance during a long and stable cycling at a cost of 20% capacity diminution as compared to pristine VS4 in RMBS. Hence, 9% CoVS4 demonstrated a capacity of 158 mAh g–1 at a current density of 500 mA g–1 with approximately 98% capacity retention after 1000 cycles. Sustainable cathodic performance is the most desirous feature for commercialization. This work provides insight realization regarding structural limitations and opportunities of VS4 for sustainable cathodic performances in RMBS with non-nucleophilic 0.25 mol/L (R-PhOMgCI)2-A1Cl3/THF (PMC) electrolyte and has laid a theoretical plus experimental foundation for future developments.
研究领域:
材料科学
·
电化学
·
电池技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）