Journal of Materials Research and Technology-JMR&T
·
2021
·
IF 5.039
Yongjie Liu,Ran Xin,Donglai Ma,Qingqing Hu,Yue Wang,Zhixiong You
Ferrovanadium nitride, which comprises V and N, is an important alloy additive for the production of high-strength low-alloy steel. As an efficient reducing agent and nitrogen source, ammonia gas is widely used in the preparation of metal nitrides. In this study, ferrovanadium nitride alloy powder is prepared by reducing and nitriding VO 2 /Fe 2 O 3 in NH 3 –H 2 gas mixtures with different nitriding potentials. Thermodynamic analysis indicate that the reduction and nitridation of VO 2 and Fe 2 O 3 is feasible. VO 2 is converted into VN, whereas Fe and Fe 4 N can be formed depend on the reaction conditions. Lower temperatures and higher nitriding potentials are beneficial to the formation of Fe 4 N. Based on Rietveld refinement analysis, the formation of Fe 4 N and the atomic occupancy of V and N in vanadium oxynitride, which is associated with the temperature, reaction time, and nitriding potential, is determined. A ferrovanadium nitride alloy powder with an O content of 0.26 wt.% is prepared by reducing and nitriding VO 2 /Fe 2 O 3 at 900 °C for 1 h at a nitriding potential of 4.4 × 10 −3 Pa −0.5 .
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
IEEE Photonics Journal
·
2025
·
IF 2.4
Yexi Sun,Qianyu Huang,Xin Guo,Maohui Yuan,Kai Han
Lanthanide-doped phosphors are of importance in the practical applications. In this work, we investigated the photoluminescence properties and random lasing behaviors of Dy3+-doped Sr2MgMoO6 phosphors synthesized by the high-temperature solid-state method. The SEM, XRD, and EDS with elemental mapping results reveal the successful fabricating of the high-quality Sr2MgMoO6 phosphors and confirm the uniform distribution of constituent elements. Structural characterization through precise Rietveld refinement confirmed that the material crystallizes in a tetragonal system with space group I4/m (No. 87), and its refined lattice parameters are also determined. The effect of different Dy3+ doping concentrations on the luminescent properties was analyzed. The optimal doping concentration for achieving efficient luminescence is fixed at 0.08 mol%. Typical emission peaks centered at 484 nm, 576 nm, 656 nm, and 756 nm of Dy3+ were observed under the blue light excitation. Additionally, random lasing phenomena were observed in the Sr2MgMoO6 phosphors when excited with a 355 nm pulsed laser under varying pump power densities. The random lasing behaviours were confirmed by the emergence of narrow emission peaks with a narrow full width at half maximum (FWHM) and the dependence of the intensity on the excitation intensity. This work highlights the potential of Dy3+-doped Sr2MgMoO6 phosphors as efficient luminescent materials and demonstrates their application in random lasing, which opens new possibilities for their use in optoelectronic and laser technologies.
研究领域:
材料科学
·
光电子学
·
光子学
·
固体物理
·
激光技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 15
·12620-12627
·
IF 2.22
Ma Xiaomeng,Li Congyi,Fan Zijia,Wu Haitao,Zhang Yuping,Zhang Zhiliang
Low temperature-sintered ceramics Nd 2 Zr 3 (MoO 4 ) 9 were successfully prepared via reaction-sintering method. The sintering behavior, microwave dielectric properties, crystal structure, and microstructure were analyzed systematically. XRD and Rietveld refinement results revealed that all samples formed a pure trigonal structure phase with the space group of R-3c. Density determination showed that ceramics possessed the highest relative density when sintered at 800 °C for 6 h. SEM image further confirmed that ceramics possessed dense and homogeneous microstructure at the optimum sintering temperature 800 °C. Far infrared spectra analysis showed the structural phonon oscillation at infrared region played an important role in polarization. Nd 2 Zr 3 (MoO 4 ) 9 ceramics obtained the optimum microwave dielectric properties of ε r = 10.01, Q × f = 55,923 GHz, τ f = − 13.81 ppm/ °C when sintered at 800 °C for 6 h.
研究领域:
材料科学
·
陶瓷
·
微波介电材料
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固体化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Qin Yu,Cheng Liu,Junxiao Liu,Da Huang,Tianlong Wen,Dainan Zhang,Huaiwu Zhang
In this study, NaMg 1- x Mn x (PO 3 ) 3 (0.00 ≤ x ≤ 0.0625) ceramics with low dielectric constant were prepared via the solid-state reaction method. The effects of Mn 2+ substitution on the microstructure and dielectric properties (at microwave and terahertz frequencies) of the NaMg(PO 3 ) 3 ceramics were studied by means of the Rietveld refinement, morphology, and ionic polarizability analysis. It is obtained that the NaMg 0.0975 Mn 0.025 (PO 3 ) 3 ceramic sintered at 880 °C for 4 h exhibited optimal dielectric properties at microwave frequencies, where ε r = 4.585, Q × f = 48,313 GHz (@17.228 GHz), and τ f = −40.83 ppm/°C. The Q × f and τ f values were changed by 74.2 % and 27.8 %, as compared to the values of 27,728 GHz and −56.52 ppm/°C for the pure NaMg(PO 3 ) 3 ceramic, respectively. For terahertz frequencies (0.2–1.0 THz), the ε r values were decreased to 3.79–3.98, and the tan δ values were between 0.0203 and 0.1152. All the experimental results indicate that this system exhibits great potentials both at microwave and terahertz frequencies.
研究领域:
材料科学
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电气工程
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陶瓷
·
介电材料
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Ke Chen,Xiaojing Bai,Xulin Mu,Pengfei Yan,Nianxiang Qiu,Youbing Li,Jie Zhou,Yujie Song,Yiming Zhang,Shiyu Du,Zhifang Chai,Qing Huang
The elemental diversity is crucial to screen out ternary MAX phases with outstanding properties via tuning of bonding types and strength between constitutive atoms. As a matter of fact, the interactions between M and A atoms largely determine the physical and chemical properties of MAX phases. Herein, Se element was experimentally realized to occupy the A site of a MAX phase, Zr 2 SeC, becoming a new member within this nanolaminated ternary carbide family. Comprehensive characterizations including Rietveld refinement of X-ray Diffraction and atom-resolved transmission electron microscopy techniques were employed to validate this novel MAX phase. The distinct thermal conduction behaviors emerged are attributed to the characteristic interactions between Zr and Se atoms.
研究领域:
材料科学
·
固体物理
·
纳米材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Xingrui Pu,Xing Cheng,Qiaohong Yan,Yueming Lin,Rentai Yan,Ruize Yang,Xiaohong Zhu
The need to develop safe solid-state lithium batteries has stimulated intense research efforts for Li + solid electrolytes. However, the low conductivity limits the development of NASICON LiZr 2 (PO 4 ) 3 (LZP) electrolyte. Here, the doping effects of Ta on the structure, surface morphologies and electrochemical properties of Li 1- x Zr 2- x Ta x (PO 4 ) 3 (LZTP, x = 0, 0.01, 0.02, 0.04, 0.06 and 0.08) solid electrolyte were analyzed. LZTP was prepared using a simple solid-state reaction route, followed by sintering at 1200 °C for 12 h. A proper content of Ta 5+ substitution for Zr 4+ is beneficial to stabilize the high conductive rhombohedral (α) phase of LZP at room temperature. Doping Ta 5+ is conducive to unblocking of Li + at the M1 site and facilitates the occupation of Li + at the M2 site, thereby expanding the pathway for Li + conduction. Rietveld refinement data demonstrated that the Zr–O and P–O bond lengths ( d Zr-O and d P-O ) increased with a decrease in Zr–O–P bond angles ( θ Zr-O-P ) as x rose. The distortions in the ZrO 6 octahedron may weaken the coulomb attraction in Li + -O 2- , resulting in a lower activation energy ( E a ) and a higher Li + conductivity. The highest room-temperature conductivity (6.06 × 10 −5 S cm −1 ) was obtained at x = 0.06, which reached 1.5 × 10 −4 S cm −1 at 50 °C. The E a was found to decrease from 0.388 eV ( x = 0) to 0.306 eV ( x = 0.06). In addition, Ta doping resulted in improved connectivity and reduced pore formation, which also contributed to the decrease in resistance. The Raman spectrum demonstrated that some phonon modes of bending vibration in PO 4 were degenerate and external modes became too weak to be observed or even disappeared as Ta content increased. This change in the modes also had an impact on the Li + conductivity. Overall, the LZTP-0.06 appears to be a promising candidate for the solid electrolyte.
研究领域:
材料科学
·
电化学
·
固态电池
✓ 已验证
产品关联
DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2024
·
IF 3.9
Xianghui Feng,Chao Zeng,Fengxiang Sui,Jingya Liu,Kai Wu,Yonghong Cheng,Bing Xiao
Herein we demonstrate the synthesis of a new out-of-plane ordered double-transition-metal MAX phase known as Mo 2 VAlC 2 . Annealing the elemental powder mixture at 1540 °C with 2.0Mo: 1.0 V: 1.3Al: 1.8C results in a high yield of 91.2 wt% for Mo 2 VAlC 2 . The crystal structure of Mo 2 VAlC 2 is determined using Rietveld refinement of powder XRD, and which crystalizes into a hexagonal lattice structure with space group P6 3 /mmc. Employing the double spherical aberration corrected transmission electron microscopy, we confirm its chemically ordering behavior of one V layer sandwiched between two Mo layers. Additionally, its two-dimensional derivative Mo 2 VC 2 T x MXene has been successfully realized by etching the Al layer of Mo 2 VAlC 2 with hydrofluoric acid. The chemical composition and microstructure of Mo 2 VC 2 T x are inspected with SEM and EDX. The resulting multilayer and intercalated Mo 2 VC 2 T x exhibit the characteristic accordion-like and paper-like appearances, respectively. This work further expands the diversity of chemically ordered double-transition-metal MAX and MXene families.
研究领域:
材料科学
·
纳米技术
·
固体化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 108
·89290-89298
·
IF 3.84
Lili Wang,Byung Kee Moon,Sung Heum Park,Jung Hwan Kim,Jinsheng Shi,Kwang Ho Kim,Jung Hyun Jeong
A novel Sm3+-doped Sr2CaWO6 (SCWO) red phosphor, synthesized though a solid-state reaction, was reported. Its crystal structure was analyzed and refined via the Rietveld full-pattern fitting method based on XRD patterns. The CASTEP module of Materials Studio was used to investigate the band structure and density of states of the SCWO. The optical band gap was calculated through the UV-vis diffuse reflectance spectrum and compared with the value predicted by the DFT method. Raman spectra were recorded to confirm the substitution of cations by Sm3+ ions. The broad W–O charge transfer band and narrow excitation band at 406 nm from Sm3+ ions have comparable intensities in SCWO:Sm3+. After the introduction of charge compensators Li+, Na+ or K+, the intensity of the near-UV excitation band at 406 nm was almost twice as much as before. The profiles of the emission spectra under excitation into the charge transfer absorption and f–f transition of Sm3+ are different, and low-symmetry Sm3+ centres are preferentially excited via f–f absorption transitions. The intensity ratios of electronic, magnetic dipole-allowed transitions under different radiations show that the charge compensators can influence the chemical environment around Sm3+.
研究领域:
材料科学
·
固体化学
·
发光材料
·
晶体学
·
电子结构理论
·
无机功能材料
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 21
·7143-7151
·
IF 4
Lu Liang,Xiaohui Li,Xiaoge Wang,Zhaoji Luo,Kun Lin,Qiang Li,Sihao Deng,Lunhua He,Xiaojun Kuang,Xianran Xing
Mixed electronic and oxide ionic conduction was enabled in digermanate-type La2−xCaxGe2O7−x/2 containing Ge3O10 chains and isolated GeO4 units by substitution of La3+ with Ca2+. The structure and solid solution limit of Ca doped La2Ge2O7 were studied by systematic experiments, including rotation electron diffraction (RED), X-ray diffraction (XRD) and neutron powder diffraction (NPD) experiments, etc. The preferred occupation of Ca2+ and oxygen vacancies was investigated by Rietveld analysis of the NPD data. The obtained conducting material La1.925Ca0.075Ge2O6.963 exhibits superior thermal stability and an order of magnitude improvement in conductivity compared to the parent La2Ge2O7 (∼9 × 10−5 S cm−1 at 1000 °C). BVEL calculations reveal that the oxygen vacancies were stabilized and transported within the framework of La2Ge2O7 by sharing oxygen and oxygen exchange between the adjacent Ge3O10 chains and GeO4 units, exhibiting a three-dimensional oxide ion transport nature.
研究领域:
无机化学
·
固态离子学
·
功能材料
·
结构化学
·
能源材料
·
晶体化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE CHINESE CHEMICAL SOCIETY
·
2025
·
IF 1.5
Hongli Yang,Ting Li,Panpan Chang,Jinshi Dong
As an important transitional alumina phase, θ-Al 2 O 3 , its structural stability directly impacts the thermodynamic properties and potential applications. In this study, the unit cell structure of θ-Al 2 O 3 was determined through Rietveld XRD refinement, and it was found that the occupancies of both two types of Al sites and two of three types of O sites were less than 1. A 1 × 5 × 2 supercell (Al 80 O 120 ) was constructed, and the effect of each type of defect on the stability of the structure was determined by molecular dynamics simulations and the calculations of the probability distribution function of the distance to mass center (P(r)) during heating. It was found that defects at the Al1 sites are more likely to cause structural instability than those at the Al2 sites; the O3 defect brings poor thermal stability to the structure due to its low occupancy.
研究领域:
材料科学
·
陶瓷
·
计算材料学
·
固态化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Lin Tang,Xuefan Zhou,Muhammad Habib,Jinzhu Zou,Xi Yuan,Yan Zhang,Dou Zhang
As a promising lead-free high-temperature piezoelectric material , BiFeO 3 –BaTiO 3 (BF-BT) is still under debate on its crystal structure, especially for the compositions in the morphotropic phase boundary (MPB). Herein, the crystal structure of (1- x )BF- x BT ceramics near the MPB with x = 0.20–0.33 was analyzed by X-ray diffraction and Raman spectroscopy . With the addition of BT, the phase transition from distorted rhombohedral to pseudo-cubic structure was determined by Rietveld refinement . Raman analysis showed the weakening interactions between the A-site cations and BO 6 octahedron, as well as the degenerated distortions of BO 6 octahedron. Intriguingly, the results of X-ray photoelectron spectroscopy suggested the inhibition of Fe 3+ reduction and decrease in oxygen vacancy concentration by the incorporation of BT. In terms of the electrical properties, the significant decline in Curie temperature , improvement in permittivity, and reduction in high-temperature dielectric loss can be observed with the increase of BT content. The increased remnant polarization, enhanced dielectric response and decreased coercive field were helpful for the piezoelectric performance. The maximum room-temperature piezoelectric coefficient of ∼160 pC/N and high-temperature piezoelectric coefficient of ∼324 pC/N were acquired in the x = 0.30 ceramics. This work provides a clear scope for further research on the structural transformation and high-temperature piezoelectric applications of BF-BT system.
研究领域:
材料科学
·
陶瓷
·
压电材料
·
晶体学
·
电学性质
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Weidong Li,Qiuyi Chen,Dongyun Zhang,Chen Fang,Song Nian,Wenxu Wang,Cong Xu,Chengkang Chang
Aiming for promoting the capacity and cycling stability of O3-type NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM), the cathode material of sodium ion batteries (SIBs) with the most potential for industrialization, Na(Ni 1/3 Fe 1/3 Mn 1/3 ) 0.99 Mo 0.01 O 1.99 F 0.01 (NFM-MoF), Na(Ni 1/3 Fe 1/3 Mn 1/3 ) 0.99 Mo 0.01 O 2 (NFM-Mo) and NaNi 1/3 Fe 1/3 Mn 1/3 O 1.99 F 0.01 (NFM-F) were successfully synthesized by solid phase method. The electrochemical performance of the doped samples was compared with that of the pristine NFM. The mechanism of the single- or dual-doping was explored by XRD Rietveld refinement and XPS. The NFM-MoF exhibits the highest initial specific discharge capacity of 137mAhg −1 at 1 C with a retention of 91.97% after 100 cycles and the smallest polarization (0.32 V), which could be contributed to the highest Ni 2+ content and highest D Na + (7.335 ×10 −13 cm 2 ·s −1 ) caused by the synergistic effect of Mo and F dual-doping. The highest Fe 3+ content in the NFM-Mo leads to the higher initial discharge capacity of 1 36 mAhg −1 at 1 C with a relative lower retention of 83.38%, which is due to the structure instability resulting from Fe migration and the lowest Mn content, than that of the NFM-F (85.31%). It illustrates that the Mn 4+ plays a crucial role in stabilizing the structure during Na + migrating. The superiority of the discharge capacity of the NFM-Mo become narrow with rates rise, due to its lower D Na + (4.229 ×10 −13 cm 2 ·s −1 ) than that of the NFM-F D Na + (5.681 ×10 −13 cm 2 ·s −1 ). It verifies that it is a diffusion control process at high rates. Mo and F dual-doping in NFM was proved to amplify the benefit of Ni 2+ increasing, meanwhile restrain undesirable Fe increasing due to the synergistic effect.
研究领域:
材料科学
·
电化学
·
储能技术
·
无机化学
·
固体物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）