CERAMICS INTERNATIONAL
·
2020
·Vol. 46
·期 10
·16524-16532
·
IF 3.83
Muhammad Yousaf,Asma Noor,Shuai Xu,Majid Niaz Akhtar,Baoyuan Wang
Yttrium iron garnet (YIG) nanoparticles (NPs) doped with rare earth (RE) metal ions (Y 2.5 Sm 0.5 Fe 5 O 12 , Y 2.5 Nd 0.5 Fe 5 O 12 ) were successfully synthesized by sol-gel auto combustion approach. The cubic crystalline structure and morphology of the prepared garnet ferrite NPs were analyzed by X-ray diffractometer (XRD) and field emission scanning electron microscopy (FESEM). The cubic crystalline garnet phase of the synthesized YIG, Sm-YIG and Nd-YIG samples was successfully achieved at 950 °C sintering temperature . The force constant and absorption bands were estimated by using Fourier transform infrared spectroscopy (FTIR). The doping effect of RE metal ions on the chemical states of YIG were examined by x-ray photoelectron microscopy (XPS). The valence band (from 12.63 eV to 13.22 eV), conduction band (from 10.89 eV to 11.34 eV) edges and optical bandgap values of RE doped YIG samples were calculated using UV–Vis spectroscopy and ultraviolet photo electron spectroscopy (UPS). The magnetic analysis of the prepared NPs was studied using vibrating sample magnetometer (VSM). The XPS analysis of RE doped YIG samples exhibit the existence of RE (Sm +3 , Nd +3 ) contents on the surface of YIG ferrite by decreasing the oxygen lattice in garnet structure. The optical bandgap (from 1.74 eV to 1.88 eV) explains the semiconducting nature of the synthesized NPs. The UPS results confirm the valence band position of YIG doped samples. The saturation magnetization and remanence of RE doped garnet ferrite samples increased from 13.45 to 18.83 emu/g and 4.06–6.53 emu/g, respectively.
研究领域:
材料科学
·
纳米科技
·
固体物理
·
无机化学
·
功能材料
✓ 已验证
DOI
高影响因子
POLYMER
·
2017
·
IF 3.684
Wei Yang,Xu Cheng,Haibo Wang,Yuansen Liu,Zongliang Du
Novel waterborne fluorinated polyurethane (WFPU) based on hydroxyl-terminated poly(fluoroalkyl methacrylates) (HTPFMA) was prepared successfully. The microstructures and micro-phase separation of WFPU were evaluated through infrared spectroscopy (FT-IR), X-ray diffraction (XRD), dynamic mechanical analysis (DMA), and scanning electron microscope (SEM). FT-IR revealed that the H-bonded carbonyl in hard domains increased with the increasing of fluorine content, resulting in enhancing the extent of micro-phase separation between hard and soft segments. XRD results indicated that the crystallinity of hard segment was enhanced with the increasing of fluorine content. The direct visual microstructures by SEM showed that the micro-phase separation was more significant when the fluorine content increased. DMA also revealed strengthened micro-phase separation with increasing fluorine content. The studies of mechanical properties confirmed that WFPU based on HTPFMA had outstanding mechanical properties. The effects of fluorine content on the static contact angles, surface free energy , and surface composition were also studied. The static contact angles of the WFPU films against water and methylene iodide reached around 108° and 84°, respectively. X-ray photoelectron spectroscopy (XPS) confirmed that the fluorine surface enrichment factor in the outermost 10 nm depth was about 10–18 fold higher than its bulk level.
研究领域:
高分子材料科学
·
表面科学
·
材料化学
·
软物质物理
·
功能涂层材料
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2023
·Vol. 53
·期 12
·2411-2419
·
IF 2.9
Mai Manfang,Liao Bin,Liao Yijun,Lin Donghai,Ma Xinzhou
GaTe thin films are electrochemically deposited on indium tin oxide for photoelectrochemical applications. The electrochemical deposition behavior of GaTe thin films in acidic solution of HTeO 2 + with Ga 3+ is studied with cyclic voltammetry combining with operando transmittance spectroscopy. Underpotential deposition of Ga on Te starts at potential of − 0.35 V. The presence of Ga 3+ in the solution can strongly suppressed the formation of H 2 Te. XPS analysis reveals that Ga-rich GaTe is deposited over a wide potential range. The photoelectrochemical performance of the thin films as photocathodes is strongly dependent on the deposition potential. The GaTe films deposited at − 1.0 V produced the highest photocurrent of about − 0.03 mA cm −2 . Meanwhile the film deposited at − 0.35 V shows improved performance during photoelectrochemical measurement, which can be ascribed to the increased GaTe content during photoelectrochemical measurements, as confirmed by XPS analysis. Graphical
研究领域:
材料科学
·
电化学
·
半导体物理
·
光电功能材料
·
能源材料
·
表面科学
·
薄膜技术
✓ 已验证
DOI
高影响因子
PHYSICA B-CONDENSED MATTER
·
2022
·
IF 2.988
Wei Zhang,Zhiwei Gu,Bingbing Zong,Yueju Fu,Kai Zhang,Yubao Li
Defects is of special importance in tuning the structure and physical properties of layered materials. Here the influence of transition metal Co vacancies on the structure and magnetism in collapsed tetragonal CaCo 2- x As 2 (0 ≤ x ≤ 0.3) solid solutions are systematically investigated. The electrical properties show metallicity in all compounds. The crystal structure refinement exhibits that the lattice constant of the c axis and c / a ratio decreases as Co vacancies increase, revealing the formation of a more collapsed tetragonal structure in CaCo 2- x As 2 . Moreover, these introduced Co vacancies suppress the antiferromagnetic Néel temperature from 80 K down to 18 K until it disappears above 10 K in CaCo 1 · 7 As 2 . X-ray photoelectron spectroscopy reveals increased Co 3+ /Co 2+ value in CaCo 2- x As 2 with higher Co vacancies, which may result in the charge balance and the gradually suppressed T N . This study offers insights into tuning and understanding the magneto-structural characteristics in ThCr 2 Si 2 -type layered materials through transition metal vacancies.
研究领域:
凝聚态物理
·
材料科学
·
固体化学
·
磁学
·
晶体工程
·
缺陷工程
✓ 已验证
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2022
·Vol. 17
·期 5
·e2790
·
IF 1.777
Bingyi Zhou,Tao Ge,Xiaoman Luo,Zhaohui Wang,Yueyue Qiao,Chuanchuan Cai,Jingyao Xu
Under the two frequency microwave conditions of 915 and 2450 MHz, orthogonal tests were designed to investigate the effects of organic acid reagent, microwave irradiation time, and mixing time of additives and coal samples on the desulfurization effect of coal. Results show that the effect of irradiation time on the experimental desulfurization efficiency under frequency microwave conditions is large and is the main factor. The desulfurization effect under 915 MHz microwave condition is better than 2450 MHz microwave condition. Two sets of experimental optimal coal samples were used for characterization and analysis. Thermogravimetric analysis revealed that the combustion temperature range of the coal samples is shortened and the integrated combustion index is considerably higher after the microwave irradiation experiment. Fourier-transform infrared spectroscopy analysis showed that the overall chemical structure of the coal samples does not change significantly after the experimental treatment. X-ray photoelectron spectroscopy analysis showed that the intensity of organic sulfur in coal samples is weakened after microwave irradiation, the characteristic peaks of thiols and thioethers are reduced to a great extent, and an increase in the intensity of sulfoxide organic sulfur is observed. On the basis of the results of experimental analysis and quantum chemical simulation calculations, the mechanism of organosulfur structure removal under the action of microwave is revealed.
研究领域:
能源化学
·
煤化学
·
环境工程
·
材料科学
·
物理化学
·
分析化学
·
清洁燃料技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）