SCRIPTA MATERIALIA
·
2021
·
IF 5.611
Lei Meng,Chu Xin Peng,Chen He,Fei Yen
The polarity of the magnetic susceptibility χ( T ) of ammonium alum NH 4 Al(SO 4 ) 2 •12H 2 O single crystals below its ferroelectric Curie temperature T C is identified to depend only on the cooling rate. To explain this, we consider reorienting distorted NH 4 + to carry weak magnetic and electric dipole moments that are linearly coupled. Slow cooling allows the dipole moments to align which enhances χ( T ) to become positive. However, due to energy degeneracy of rotational motion and geometric frustration of the NH 4 + , faster cooling rates render the system to become an orientational glass state causing χ( T ) to remain negative. Specific heat measurements also show the presence of excess entropy below a negative anomaly near 53 K. Our findings identify a possible new class of non-equilibrium system with potential applications in non-volatile memory devices.
研究领域:
物理学
·
材料科学
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产品关联
DOI
高影响因子
LANGMUIR
·
2022
·
IF 4.331
Chenming Han,Xiaoyan Yuan,Lixia Ren
A magnetic surfactant, which combines the properties of a surfactant with magnetic responsiveness, shows great potential in biotechnology, separation, adsorption, and catalysis, especially in non-invasive manipulation through a magnetic field. However, a molecularly magnetic surfactant is usually paramagnetic for the amorphous and less ordered structures. In this work, magnetic surfactant 1-methyl-3-hexadecane-imidazolium [MnCl2Br] (C16M[Mn]) is reported to self-assemble in water. The C16M[Mn] magnetic surfactant self-assembles in water to form a lamellar hydrogel from 10 to 50 wt % at and below room temperature. The hydrogel changes from a gel to a sol at 30 °C, and the hexadecane chains in the hydrogel change from noncrystalline to crystalline at 0 °C. In the hydrogel state, the lamellar domain spacing is varied from 36 to 45 nm depending on the concentration and self-assembly temperature. After self-assembly, the magnetic susceptibility of the freeze-dried magnetic surfactant is increased. Most important is the fact that the freeze-dried sample at a high concentration (40–50 wt %) shows the highest magnetic susceptibility, which is related to the closer molecular packing and the more ordered structures. The self-assembly-induced increase in magnetic susceptibility provides a method for improving the magnetic properties of a magnetic surfactant.
研究领域:
材料科学
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化学
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生物技术
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产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2019
·
IF 4.309
Fei Yen,Lei Meng,Tian Gao,Sixia Hu
Different types of magnetism arise mainly from how electrons move and interact with each other. In this work, we show how protons (H+) also exhibit magnetic behavior. We measured the magnetic susceptibility of the ammonium halides and identified pronounced increases at 232, 233, and 243 K for NH4I, NH4Br, and NH4Cl, respectively, all of which coincide with the geometric ordering of their ammonium cations. With extensive literature establishing the fact that the ammonium cations exhibit rotational motion even toward the lowest temperatures, we take into account that the orbital motion of the protons carries a magnetic moment and find it to be larger than that of the paired electrons. Consequently, the structural phase transitions are magnetically driven as the system attempts to lift 8-fold energy degeneracies of the proton orbitals via Jahn–Teller distortions. Our findings identify that NH4+ cations are capable of comprising magnetism which appears to be ubiquitous in ammonia-based molecular solids.
研究领域:
物理学
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材料科学
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产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·Vol. 36
·期 29
·2401538
·
IF 27.4
Hui Du,Qiyue Wang,Bo Zhang,Zeyu Liang,Canyu Huang,Dao Shi,Fangyuan Li,Daishun Ling
The identification of metastasis “seeds,” isolated tumor cells (ITCs), is of paramount importance for the prognosis and tailored treatment of metastatic diseases. The conventional approach to clinical ITCs diagnosis through invasive biopsies is encumbered by the inherent risks of overdiagnosis and overtreatment. This underscores the pressing need for noninvasive ITCs detection methods that provide histopathological-level insights. Recent advancements in ultra-high-field (UHF) magnetic resonance imaging (MRI) have ignited hope for the revelation of minute lesions, including the elusive ITCs. Nevertheless, currently available MRI contrast agents are susceptible to magnetization-induced strong T 2 -decaying effects under UHF conditions, which compromises T 1 MRI capability and further impedes the precise imaging of small lesions. Herein, this study reports a structural defect-enabled magnetic neutrality nanoprobe (MNN) distinguished by its paramagnetic properties featuring an exceptionally low magnetic susceptibility through atomic modulation, rendering it almost nonmagnetic. This unique characteristic effectively mitigates T 2 -decaying effect while concurrently enhancing UHF T 1 contrast. Under 9 T MRI, the MNN demonstrates an unprecedentedly low r 2 / r 1 value (≈1.06), enabling noninvasive visualization of ITCs with an exceptional detection threshold of ≈0.16 mm. These high-performance MNNs unveil the domain of hitherto undetectable minute lesions, representing a significant advancement in UHF-MRI for diagnostic purposes and fostering comprehensive metastasis research.
研究领域:
医学影像学
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2017
·
IF 3.648
Li-rong Nie,Shun Yao,Bing Dong,Xin-lu Li,Hang Song
In this paper, five novel cholinium-based organic magnetic ionic liquids (MILs) were synthesized. The carbon chain links to the nitrogen atom from cationic nucleus. The MILs were comprehensively identified by FT-IR, HPLC, UV–Vis, 1 H NMR and ESI-MS. The MILs have interesting performance to form aqueous two-phase system and can respond to the external magnetic field after the formation of aqueous two-phase system, which can assists magnetically phase separation. The magnetic susceptibility of the MILs was measured at 298 K. Other physical properties such as conductivities, acidity and density were measured in range of 278.15 K to 323.15 K for further application investigation. Satisfactory results were obtained after the data of physical properties were correlated. Based on the measurements and correlations above, some discussions were carried out, including the ion association and ion diffusion , the influences of MILs carbon chain and temperature on the molar conductivity , the influences of the cation size on the molar volume , acidity variation of the MILs.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2022
·
IF 2.042
Jun Cao,Qi Sun,Peng Wang,Jie Shen,Xue Dai
In order to solve the problem that separating zeolite 4A from solutions, we have synthesized Fe3O4/zeolite 4A magnetic nanocomposite by hydrothermal method. It is characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), Vibrating Sample Magnetometer (VSM), scanning electron microscope (SEM) and Brunner-Emmet-teller (BET). The XRD result shows that Fe3O4/zeolite 4A magnetic nanocomposite has a good crystal structure. It also shows that Fe3O4/zeolite 4A magnetic nanocomposite contains two phases of zeolite 4A and Fe3O4 MNP. The optimal sample (Z-2) was judged by the calculation of crystallinity. The successful combination of zeolite 4A and Fe3O4 MNP was visually observed through SEM technology. The functional groups of Fe3O4/zeolite 4A magnetic nanocomposite were characterized by FTIR technology. The TEM result shows that some Fe3O4 MNPs enter zeolite 4A, which further clarifies the microstructure of Fe3O4/zeolite 4A magnetic nanocomposite. N2 adsorption-desorption technique confirms that Fe3O4/zeolite 4A magnetic nanocomposite SBET is 55.3374 m2/g and Dave is 9.7128 nm. VSM result shows that Fe3O4/zeolite 4A magnetic nanocomposite magnetization is 18.4534 emu/g. Simulation experiment shows that Fe3O4/zeolite 4A magnetic nanocomposite exhibit a fast response to an external magnetic field.
研究领域:
材料科学
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纳米技术
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化学工程
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磁性材料
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2018
·
IF 4.513
Xuezhi Dai,Jinhang Li,Yuzhi Ma,Xianqiu Lan,Hang Song
The application of guanidinium-based ionic liquids (ILs) is a newly emerging area in the fields of extraction desulfurization. Herein, four novel pentaalkylguanidinium-based magnetic room temperature ionic liquids (MRTILs) [C n TMG][FeCl 3 Br] (n = 2, 4, 6, 8) were synthesized and characterized by FT-IR, Raman and HRMS (ESI) spectra. The physical properties including thermal stability, density, viscosity, conductivity and magnetic properties were determined and revealed that the MRTILs were liquids at room temperature and have good thermal stability ( T d > 250 °C), high magnetic susceptibility (>3.8 × 10 5 emu·g −1 ) and low viscosities (<160 mPa·s, 25 °C). Moreover, the mutual solubility behaviors for binary systems of MRTILs with representative non-polar organic solvents (cyclohexane, n -octane) were measured at temperatures from 5 to 65 °C, showed a low miscibility between MRTILs and organic solvents and a typical lower critical solution temperature (LCST) phenomenon. The results are supposed to provide useful information for further application as “green” liquid desulfurization extractants or others potential dispersive liquid-liquid microextraction applications.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2025
·Vol. 38
·期 6
·231
·
IF 1.7
Liu Wanxia,Gao Yuxia,Li Yaning,Li Yulong,Ren Weijie,Sun Xin,Li Xiaofeng,Wang Mingli
The synthesis, structure, and magnetic properties of Ba 3 REB 9 O 18 (RE = Dy-Yb) compounds were investigated. Rietveld Refinement of the X-ray diffraction (XRD) data confirms that all compounds crystallize in a hexagonal Ba 3 YB 9 O 18 -type structure with space group P 6 3 /m (No. 176) and Pearson symbol hP 62. The lattice parameters a and c increase linearly with the increasing ionic radii of the RE 3+ ions. RE 3+ ions form two-dimensional triangular layers in the ab plane, which are separated by non-magnetic Ba/B-O polyhedra. The magnetic susceptibility measurement reveals no long-range magnetic order or spin glass behavior in any of the compounds above 2 K. The negative Curie-Weiss temperatures indicate dominant antiferromagnetic (AFM) exchange interactions between the RE 3+ ions. The combination of triangular lattice and antiferromagnetic interaction suggests this family of compounds is a promising system for researching magnetic frustration.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2018
·
IF 4.513
Xuezhi Dai,Xiaolian Qiang,Jinghang Li,Tian Yao,Zhixia Wang,Hang Song
A series of magnetic ionic liquids surfactants (MILSs) containing alkyltrimethylammonium fragment {dodecyltrimethylammonium bromotrichloroferrate (III) ([DTA][FeCl 3 Br]), tetradecyltrimethylammonium bromotrichloroferrate (III) ([TTA][FeCl 3 Br]), cethyltrimethylammonium bromotrichloroferrate (III) ([CTA][FeCl 3 Br]), and stearyltrimethylammonium bromotrichloroferrate (III) ([STA][FeCl 3 Br])} were synthesized and characterized by FT-IR, Raman and MS (ESI) spectra. The physical properties including thermal stability, density and magnetic susceptibility were determined, which revealed that the MILSs had good thermal stability ( T d > 210 °C) and considerable magnetic susceptibility ( x g > 3.2 × 10 −5 emu·g −1 ). The critical micelle concentration (CMC) values of MILSs aqueous solutions based both on electrical conductivity method and surface tensiometry demonstrated that MILSs had better surface active than the corresponding nonmagnetic parent surfactants {dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), cethyltrimethylammonium bromide (CTAB) and stearyltrimethylammonium bromide (STAB)}. Moreover, the surface tensiometry in a magnetic field revealed that the MILSs showed a magnetically induced reduction in surface tension. With surface active and magneto-responsivity bi-functional properties, allow these MILSs pretend to be manipulated noninvasively and reversibly by an applied external magnetic field in further potential applications such as colloid and surface chemistry.
研究领域:
化学
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材料科学
·
界面科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Shuaikun Li,Yanhong Wang,Haibo Li,Hang Liu,Yun Lv,Hongcheng Lu
A novel magnetic alkaline-earth chromium fluoroiodate Ba 2 CrIO 3 F 6 has been successfully synthesized via the hydrothermal method and characterized for its structure and physical properties by single crystal X-ray diffraction, attenuated total reflection (ATR) infrared spectroscopy, UV-vis-NIR spectroscopy, thermal stability, as well as magnetic susceptibility, and specific heat. The compound Ba 2 CrIO 3 F 6 contains the [CrIO 3 F 6 ] 4- spin chains which are further separated by nonmagnetic Ba 2+ cations. The magnetic susceptibility results show no long-range magnetic order down to 2 K, which are further confirmed by specific heat measurement. The positive Weiss temperature and the increase of χT - T curve at low temperature both suggest the magnetic exchange interactions through the Cr 3+ −IO 4 F−Cr 3+ pathway are unexpectedly ferromagnetic. Our work illustrates that it is promising to use the IO x F y anion group for the design and construction of novel magnetic materials with ferromagnetic exchange interactions for potential spintronics device applications.
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 29
·10079-10091
·
IF 6.4
Sheng’an Yang,Junfeng Li,Jin Hu,Ruidong Xu,Hui Zhang,Lingde Kong,Xiang Liu,Ji Ma,Qingming Chen
Polycrystalline manganites with outstanding anisotropic magnetoresistance and temperature coefficient of magnetization have great potential for application in magnetic sensors. Recent studies have shown that altering the ion occupation ratio would induce Jahn–Teller distortion and affect the spin–orbital coupling effect, consequently enhancing anisotropic magnetoresistance and temperature coefficient of magnetization. In this study, single-phase polycrystalline La0.7−xGdxCa0.3MnO3 ceramics were fabricated via a simple nonaqueous sol–gel technique. The optimal Gd doping concentration induced the strongest Jahn–Teller distortion, as was confirmed through the Curie–Weiss behavior of the ceramics. Finally, these ceramics demonstrated the relatively large anisotropic magnetoresistance and temperature coefficient of magnetization (−30% and −28.1%/K, respectively) values under a low magnetic field of 1 T. The enhanced anisotropic magnetoresistance properties were derived from the spin–orbital coupling effect as demonstrated by the classical transport model.
研究领域:
材料科学
·
磁学
·
陶瓷
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2024
·
IF 3.2
Hui Li,Shuang Li,Yanhong Wang,Yaling Dou,Hongcheng Lu
We prepared a layered antiferromagnet KNiB 4 O 6 F 3 1 by hydrothermal synthesis, and characterized its structure and physical properties by X-ray diffraction, magnetization and specific heat measurements as well as thermal stability, FTIR and UV–vis–NIR measurements. 1 consists of layers of composition [NiB 4 O 6 F 3 ] - separated by layers of K + cations. And Ni 2+ ions are arranged in slightly distorted triangular pattern in each [NiB 4 O 6 F 3 ] - layer. The magnetic susceptibility measurements indicate no divergence between the zero-field-cooled and field-cooled curves down to 7.9 K, below which a long-range order takes place as verified by specific heat measurements. The M ( H ) curve linearly increases when the field is weak (below ∼2 T), confirming that the ground state of 1 is antiferromagnetic. At 7 T, the magnetization of 1 is 1.67 μ B which is lower than the saturation magnetization.
研究领域:
材料科学
·
固体物理
·
无机化学
·
磁学
·
晶体学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）