Journal of Physical Chemistry C
·
2024
·
IF 3.3
Xinmiao Gai,Jia Qu,Nan Zhang,Cun You,Fuqing Zhang,Tao Lv,Qiang Tao,Pinwen Zhu,Yan Li,Xin Wang
Bi2Ru2O7 is a weak metal pyrochlore with static disorder from lone-pair electrons. The suppression of static disorder can be observed by in situ Raman spectroscopy, and the abnormal turning point in resistivity can be found at high pressure. X-ray photoelectron spectroscopy (XPS) of bismuth and ruthenium, low-temperature magnetic susceptibility, and magnetization curve were studied, indicating that there were different valence states between bismuth and ruthenium. The in situ high-pressure structure evolution and conductivity in Bi2Ru2O7 were investigated up to 30.4 and 32.7 GPa, respectively. The electronic structure evolution was studied by first-principles calculations up to 30.0 GPa. Some of the Raman peaks related to static disorder were suppressed at around 2.5 and 18.0 GPa, respectively. The [RuO6] octahedron was compressed and distorted with pressure, and the triangular distortion increased in the range of 18.0 and 24.4 GPa. The high-pressure resistivity was measured by the four probe method. It slowly decreased at first and then increased slowly after 2.5 GPa due to the effects of static disorder and the applying pressure. After 18.0 GPa, the resistivity increased rapidly because of the pressure-induced lattice distortion, which led to the weakening of the conductivity of the sample under high pressure. All observations showed that the lattice distortion was influenced by the combined effects of static disorder and pressure before 18.0 GPa, which caused the resistivity to decrease first and then increase. As static disorder is suppressed, Bi2Ru2O7 is close to standard pyrochlore and the conductivity after 18.0 GPa, which is consistent with the theoretical calculation results of band gap.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2025
·
IF 3.2
Chuyi Zhang,Jiaxin Liu,Zhi Sun,Yuning Liang,Qun Xu
With the development of spintronics, ferromagnetic nanomaterials have shown unique advantages in the fields of information storage and quantum computation. The ABO3-type perovskite oxide ZnSnO3 is expected to realize d0 ferromagnetism due to its tunable crystal structure and unique electron arrangement. In this work, for the first time, the inhomogeneous oxygen octahedral structural distortion along the c-axis induced by SC CO2 can be found in 2D ZnSnO3, i.e., distortion of ZnO6 is larger than that of SnO6, and they are served as the structural basis for the generation of room-temperature ferromagnetism. In addition, combining the change in the concentration of the oxygen vacancies to ultimately realize the room-temperature d0 ferromagnetism in ZnSnO3 (Tc = 400 K, Ms = 0.1123 emu/g) can be presented. Therefore, this study establishes a new strategy for the development of transition metal-free ferromagnetic materials for the application of spintronic devices at room temperature.
研究领域:
材料科学
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凝聚态物理
·
纳米材料
·
自旋电子学
·
功能氧化物
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晶体结构工程
✓ 已验证
产品关联
DOI
高影响因子
Minerals
·
2022
·Vol. 12
·期 8
·994
·
IF 2.818
Qiuyu Zeng,Jun Xie,Wei Zhou,Jinbo Zhu,Liangliang Liu,Jianqiang Yin,Wenliang Zhu
The distortion process of kaolinite annealed from 25 °C to 550 °C for different holding times can be characterized using a thermogravimetric/differential scanning calorimeter (TG/DSC) for thermal analysis, X-ray diffraction (XRD) for establishing the crystal structure, the Fourier transform infrared spectrum (FTIR) for identifying the functional groups, and a scanning electron microscope (SEM) for establishing the microstructure. Dehydroxylation is the main reaction during annealing from 25 °C to 550 °C and leads to kaolinite crystal distortion. A stable crystal structure during distortion was obtained by optimizing the bulk phase with quantum chemistry. Then, the crystal structure was studied by using ab initio multiple scattering calculations for X-ray absorption of the fine structure (XAFS). The results of X-ray absorption near the edge structures (XANES) determined that peak shifts and intensity phases slightly increased. The crystal structure distortion of kaolinite during annealing can be explained by the experimental and simulation results. This work provides theoretical support for identifying kaolinite with different degrees of distortion and has the potential for further developments in coal gangue separation.Keywords:coal and gangue;kaolinite;distortion;multiple scattering computation
研究领域:
矿物学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
LUMINESCENCE
·
2020
·Vol. 36
·期 1
·237-246
·
IF 1.855
Feng-Nian Wu,Hua-Jian Yu,Yan-Yan Hu,Hua-Di Zhang,Rui Zhang,Jing Li,Bing Liu,Xu-Ping Wang,Yu-Guo Yang,Lei Wei
(Ca 1-x Eu x )WO 4 (x = 0–21 mol%) phosphors were prepared using the classical solid-state reaction method. The influence of Eu 3+ ion doping on lattice structure was observed using powder X-ray diffraction and Fourier transform infrared spectroscopy. Furthermore, under this influence, the luminescence properties of all samples were analyzed. The results clearly illustrated that the element europium was successfully incorporated into the CaWO 4 lattice with a scheelite structure in the form of a Eu 3+ ion, which introduced a slight lattice distortion into the CaWO 4 matrix. These lattice distortions had no effect on phase purity, but had regular effects on the intrinsic luminescence of the matrix and the f–f excitation transitions of Eu 3+ activators. When the Eu 3+ concentration was increased to 21 mol%, a local luminescence centre of [WO 4 ] 2− groups was detected in the matrix and manifested as the decay curves of [WO 4 ] 2− groups and luminescence changed from single exponential to double exponential fitting. Furthermore, the excitation transitions of Eu 3+ between different energy levels (such as 7 F 0 → 5 L 6 , 7 F 0 → 5 D 2 ) also produced interesting changes. Based on analysis of photoluminescence spectra and the chromaticity coordinates in this study, it could be verified that the nonreversing energy transfer of [WO 4 ] 2− →Eu 3+ was efficient and incomplete.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Ming-Yuan Yan,Xiao-Yu Zhang,Li-Huai Shu,Li-Da Chen,Jian Guo,Yu Xing,Ji Zhang,Feng-Zhen Huang,Shan-Tao Zhang
Rare-earth titanate pyrochlores have attracted considerable attention for their unique magnetic frustration. Among those compounds, Yb2Ti2O7, a candidate for quantum spin ice, has been extensively studied in its magnetic ground state. However, works on its dielectric property and structure-property relationship lag far more behind. Here, by preparing and investigating nonstoichiometric Yb2–xTi2O7−δ (x = 0–0.15) ceramics, we demonstrate that the samples with x ≤ 0.05 maintain a single-pyrochlore phase, but the nonstoichiometry arouses significant structural distortion and increased oxygen vacancy. As a result, the ferromagnetism, indicated by a positive Curie-Weiss temperature, decreases almost linearly with increasing x value. Remarkably composition-dependent low-temperature dielectric relaxations have been observed. In addition, through introducing nonstoichiometry, the relaxor degree of dielectric behavior is enhanced, and the dielectric curve shows an altered shape. The origin of this dielectric relaxation is attributed to the increased structural distortion reflected by the changed bond length/angle, since there is no phase transition in 90–300 K. Our work gives a comprehensive view on the structural, magnetic, and dielectric properties of Yb2Ti2O7, which is instructive for further work on pyrochlores.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Carbon Neutralization
·
2025
·Vol. 4
·期 3
·e70014
·
IF 12
Dai-Huo Liu,Chunyan Xu,Fang Xu,Yaozhi Liu,Ao Wang,Cheng Yun,Mengqin Song,Jialin Zheng,Liang Wang
The lattice distortion resulting from the Jahn–Teller effect (JTE) at the Mn redox center typically induces irreversible phase transitions and structural degradation, which in turn diminishes the reversible capacity and long-term cycling performance. Here, N-doped carbon quantum dots (N-CDs) grafted to the surface of 3 × 3 tunnel todorokite-type MnO 2 (TMO) nanosheet (abbreviated to TMO@N-CDs) are designed. The adsorption of N-CDs promoted the charge transfer and redistribution between Mn and O and promoted the closer electron cloud overlap between Mn and O, thus enhancing the bonding strength of Mn–O bonds, stabilizing the lattice structure, inhibiting JTE, and realizing reversible H + /Zn 2+ storage. Meanwhile, a significant amount of N-CDs can increase active sites of TMO nanosheet, enhance the binding ability with metal ions, and accelerate the ion diffusion kinetics, thus realizing stable electrochemical performances. The density functional theory (DFT) calculation shows that there is obvious orbital overlap between Mn and O in [MnO6] octahedron, which further quantifies the strong interaction between Mn and O through interphase synergy between N-CDs and TMO. The reversible (de)insertion behavior dominated by H + during charging and discharging was proved by operando XRD and ex-situ SEM. As expected, the obtained TMO@N-CDs cathode exhibits remarkable electrochemical properties in terms of high reversible capacity, good rate performance, and satisfactory cycling stability (after 1000 cycles, the specific capacity remains 96.02%).
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2018
·
IF 4.7
Rajaboopathi Mani,Huaidong Jiang,Santosh Kumar Gupta,Ziqing Li,Xiulan Duan
The europium ion probes the symmetry disorder in the crystal structure, although the distortion due to charge compensation in the case of aliovalent dopant remains interesting, especially preparation involves low and high temperatures. This work studies the preparation of the β-Ca2SiO4 (from here on C2S) particle from Pechini (C2SP) and hydrothermal (C2SH) methods, and its luminescence variance upon doping with Eu2+ and Eu3+ ions. The blue shift of the charge-transfer band (CTB) in the excitation spectra indicates a larger Eu3+–O2– distance in Eu3+ doped C2SH. The changes in vibrational frequencies due to stretching and bending vibrations in the FTIR and the Raman spectra and binding energy shift in the XPS analysis confirmed the distorted SiO44– tetrahedra in C2SH. The high hydrothermal temperature and pressure produce distortion, which leads to symmetry lowering although doping of aliovalent ion may slightly change the position of the Ca atoms. The increasing asymmetry ratio value from C2SP to C2SH clearly indicates that the europium ion stabilized in a more distorted geometry. It is also supported by Judd–Ofelt analysis. The concentration quenching and site-occupancy of Eu3+ ions in two nonequivalent sites of C2S were discussed. The charge state and concentration of europium ions in C2SP and C2SH were determined using X-ray photoelectron spectroscopy measurements. The C2S particles were studied by X-ray powder diffraction, FTIR, Raman, BET surface area, TGA/DTA, electron microscopy, XPS, and luminescence spectroscopy. The impact of citrate ion on the morphology and particle size of C2SH has been hypothesized on the basis of the microscopy images. This study provides insights that are needed for further understanding the structure of C2S and thereby improves the applications in optical and biomedical areas and cement hydration.
研究领域:
材料科学
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光学
·
生物医学工程
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2018
·
IF 4.7
Qiming Wang,Shourui Li,Qiang He,Wenjun Zhu,Duanwei He,Fang Peng,Li Lei,Leilei Zhang,Qiang Zhang,Lijie Tan,Xin Li,Xiaodong Li
Zinc oxide, ZnO, an important technologically relevant binary compound, was investigated by reciprocating compress the sample in a diamond anvil cell using in situ high-pressure synchrotron X-ray diffraction at room temperature. The starting sample (∼200 nm) was compressed to 20 GPa and then decompressed to ambient condition. The quenched sample, with average grain size ∼10 nm, was recompressed to 20 GPa and then released to ambient condition. The structural stability and compressibility of the initial bulk ZnO and quenched nano ZnO were compared. Results reveal that the grain size and the fractional cell distortion have little effect on the structural stability of ZnO. The bulk modulus of the B4 (hexagonal wurtzites structure) and B1 (cubic rock salt structure) phases for bulk ZnO under hydrostatic compression were estimated as 164(3) and 201(2) GPa, respectively. Importantly, the effect of pressure in atomic positions, bond distances, and bond angles was obtained. On the basis of this information, the B4-to-B1 phase transformation was demonstrated to follow the hexagonal path rather than the tetragonal path. For the first time, the detail of the intermediate hexagonal ZnO, revealing the B4-to-B1 transition mechanism, was detected by experimental method. These findings enrich our knowledge on the diversity of the size influences on the high-pressure behaviors of materials and offer new insights into the mechanism of the B4-to-B1 phase transition that is commonly observed in many other wurzite semiconductor compounds.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Jingfang Zhou,Pifu Gong,Mingjun Xia,Aimin Ji,Lifang Zhang,Huiqiang Wu,Qian Wu
Replacing alkali metals (K, Na atoms) by an alkaline-earth metal (Ba atom), α-Ba3Sc2(BO3)4 (high-temperature phase) is successfully obtained by a molten salt method, taking Ba2K1.6Na0.4Sc2(BO3)4 as the parent template. Although both of them exhibit similar layered structures composed of ScO6 and BO3 units, α-Ba3Sc2(BO3)4 shows largely distorted ScO6 octahedra (Δd = 0.56) forced by the uniform tension of a larger space effect from BaO12 polyhedrons, rather than regular ScO6 octahedra like in Ba2K1.6Na0.4Sc2(BO3)4. Experimental measurements and calculated analyses elucidate that distorted ScO6 octahedra in α-Ba3Sc2(BO3)4, displaying a second-order Jahn–Teller (SOJT) effect, enlarge the experimental birefringence up to 0.14@550 nm, while Ba2K1.6Na0.4Sc2(BO3)4 with regular ScO6 octahedra only shows Δn = 0.11 under the same condition. In addition, other optical and thermal properties of the two title compounds were characterized. The experimental results indicate that Ba2K1.6Na0.4Sc2(BO3)4 and α-Ba3Sc2(BO3)4 are promising birefringent materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Xiao Wu,Peng Wang,Xingan Jiang,Shuyao Cao,Jinfeng Lin,Rui Xiong,Zhenhuan Zheng,Min Gao,Chunlin Zhao,Tengfei Lin,Cong Lin,Baisheng Sa
Photoferroelectrics that involve strong light-matter coupling are regarded as promising candidates for realizing bulk photovoltaic and photoelectric effects via light absorption. Nonetheless, understanding the photoresponse mechanism or modulation of performance from a microscopic point of view is scarcely explored through quantification of macroscopic properties. Herein, we design a model material, Gd3+-doped (K0.5Na0.5)NbO3 ferroelectric-transparent ceramics, and present an advantageous strategy to enhance the optoelectronic coupling through joint modulations of lattice distortion and oxygen vacancies, along with inner defects and ferroelectric domains. Significantly, their microcosmic manipulation can be intuitively and facilely evaluated by the optical transparency of each ceramic. An approximately 104 fold increase in conductivity under ultraviolet irradiation was produced. Under the cocoupling between external physical fields, the synergy of photoelectric stimulation increased the photoconductivity of the ceramics by 13.89 times. Additionally, a significant increase (4.5-fold) in the current output from the photovoltaic effect was achieved via ferroelectric domains of moderate size, whose size could be easily assessed by optical transmittance. In situ microscopic observations confirmed that the configuration of oxygen vacancy-dependent ferroelectric domains contributes to the enhanced optoelectronic response. This research provides a distinct way to develop inexpensive optocoupler devices and meet the requirements for multifunctional integration in single photoferroelectrics.
研究领域:
材料科学
·
光学
·
电子工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Yaqiang Wang,Jiaman Wei,Yi Wu,Wei Yu,Xin Guo
Crystalline structures, as the basics of materials, are tightly associated with transport properties. Designing a structure through doping, alloying, and phase engineering to optimize thermoelectric transport properties has always been a crucial strategy in thermoelectrics. In this work, hybrid architectures containing an inherently long-range, nearly cubic framework as well as localized short-range noncubic lattice distortions, are designed in the pristine CuInTe2 chalcopyrites by a unique high-pressure technology. As a result, the long-range order structures motivate degeneracy in electronic bands, markedly improving the electrical transport properties. Meanwhile, suppressed lattice thermal conductivity due to strong phonon scattering is achieved by the short-range disorder structures composed of dense dislocations introduced by pressure. The above incorporation effects lead to a distinguished thermoelectric performance of zT = 1.13 at 773 K for pristine CuInTe2 prepared under 3 GPa. This study demonstrates the bright potential of high pressure as a significant approach in designing bespoke crystalline structures for tuning thermoelectric transport properties.
研究领域:
材料科学
·
热电材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TOXICOLOGY LETTERS
·
2023
·
IF 3.5
Jingjing Qu,Yinjing Zhang,Chunxia Liu,Qianqian Xie,Tong Ou,Bolin Fan,Yan Song
Anthraquinone is a recently identified contaminant present in teas globally, and its potential teratogenic and genotoxic impacts have yet to be fully comprehended. Hence, this study's objective was to determine anthraquinone's genotoxicity using various studies such as the Ames test , Mammalian erythrocyte micronucleus test, and in-vitro mammalian chromosome aberration study. Additionally, the study assessed its effects on maternal gestational toxicity and the fetus's teratogenicity through prenatal developmental toxicity research in rats. Results indicated that anthraquinone did not manifest mutagenic effects on Salmonella typhimurium histidine-deficient, did not cause chromosomal aberrations in Chinese hamster ovary cell subclone CHO-K1, and did not exhibit a genotoxic effect on mouse bone marrow erythrocytes. However, in the prenatal developmental toxicity study, administering anthraquinone orally to pregnant rats from day 5 to day 19 of gestation resulted in decreased body weight and food consumption of pregnant rats, along with a higher number of visceral malformations in the fetuses in the highest dose group (217.6 mg/kg BW). Additionally, two pregnant rats died in this group. The study has established the no observed adverse effect level (NOAEL) as 21.76 mg/kg BW, while the lowest observed adverse effect level (LOAEL) was 217.6 mg/kg BW.
研究领域:
毒理学
·
遗传学
·
生殖医学
✓ 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）