JOURNAL OF PHYSICS-CONDENSED MATTER
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2021
·Vol. 33
·期 26
·265701
·
IF 2.333
Chengping He,Xue Ming,Qing Li,Xiyu Zhu,Jin Si,Hai-Hu Wen
Recently, superconductivity at about 9–15 K was discovered in Nd1−xSrxNiO2 (Nd-112, x ≈ 0.125–0.25) infinite-layer thin films, which has stimulated enormous interests in related rare-earth nickelates. Usually, the first step to synthesize this 112 phase is to fabricate the RNiO3 (R-113, R: rare-earth element) phase, however, it was reported that the 113 phase is very difficult to be synthesized successfully due to the formation of unusual Ni3+ oxidation state. And the difficulty of preparation is enhanced as the ionic radius of rare-earth element decreases. In this work, we report the synthesis and investigation on multiple physical properties of polycrystalline perovskites Sm1−xSrxNiO3 (x = 0, 0.2) in which the ionic radius of Sm3+ is smaller than that of Pr3+ and Nd3+ in related superconducting thin films. The structural and compositional analyses conducted by x-ray diffraction and energy dispersive x-ray spectrum reveal that the samples mainly contain the perovskite phase of Sm1−xSrxNiO3 with small amount of NiO impurities. Magnetization and resistivity measurements indicate that the parent phase SmNiO3 undergoes a paramagnetic–antiferromagnetic transition at about 224 K on a global insulating background. In contrast, the Sr-doped sample Sm0.8Sr0.2NiO3 shows a metallic behavior from 300 K down to about 12 K, while below 12 K the resistivity exhibits a slight logarithmic increase. Meanwhile, from the magnetization curves, we can see that a possible spin-glass state occurs below 12 K in Sm0.8Sr0.2NiO3. Using a soft chemical reduction method, we also obtain the infinite-layer phase Sm0.8Sr0.2NiO2 with square NiO2 planes. The compound shows an insulating behavior which can be described by the three-dimensional variable-range-hopping model. And superconductivity is still absent in the polycrystalline Sm0.8Sr0.2NiO2.
研究领域:
材料科学
·
凝聚态物理
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DOI
PubMed
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-7
·
IF 5.578
Tian Junlong,Zhang Wang,Huang Yiqiao,Liu Qinglei,Wang Yuhua,Zhang Zhijian,Zhang Di
A carbon-matrix nickel composite magnetoplasmonic film with a 3D sub-micron periodic triangular roof-type antireflection structure (SPTAS) was fabricated via a simple and promising method that combines chemosynthesis with biomimetic techniques. The Troides helena (Linnaeus) forewing (T_FW) was chosen as the biomimetic template. The carbon-matrix Ni wing fabricated via electroless Ni deposition for 6 h (CNMF_6h) exhibits enhanced infrared absorption. Over a wavelength range (888–2500 nm), the enhancement of the infrared absorption of CNMF_6h is up to 1.85 times compared with the T_FW. Furthermore, infrared excitation induces a photothermal effect that results in variation in the magnetic properties of the carbon-matrix Ni wing. The magnetic properties were also confirmed using atomic force microscopy (AFM) and magnetic force microscopy (MFM). The good correlation between the AFM and MFM images demonstrates that the surface of the SPTAS of CNMF_6h exhibits strong magnetic properties. The infrared induced photothermal effect that results in magnetic variation is promising for use in the design of novel magnetoplasmonic films with potential applications in infrared information recording and heat-assisted magnetic recording.
研究领域:
材料科学
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光学
·
磁学
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DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2024
·Vol. 12
·期 21
·7644-7651
·
IF 5.7
Zechao Xu,Weiyi Lu,Kelan Yan,Runhua Fan,Ningzhong Bao
Single-phase metamaterials are a group of attractive alternatives to ordered double negative metamaterials (DNMs) that exhibit negative permittivity (ε < 0) and negative permeability (μ < 0) with periodic unit cells. However, achieving double negative electromagnetic properties in a single-phase material in the radio-frequency range is challenging. This study presents the synthesis of the single-phase metamaterial, selenospinel CuxZn1−xCr2Se4, from metallic powders through a simple solid-state reaction process. The double negative values of ε and μ were observed in the frequency range of 484–1000 MHz for Cu0.8Zn0.2Cr2Se4 (x = 0.2) and 638–1000 MHz for Cu0.6Zn0.4Cr2Se4 (x = 0.4). The negative value of ε is attributed to the plasmonic state of delocalized carriers in the metallic ferromagnetic CuCr2Se4 and can be described using the Drude model. The suppression of magnetic resonance induced by the eddy current was alleviated through appropriate doping of the Zn element. Based on the skin effect, a theoretical model was constructed to elucidate the magnetic resonance-dependent negative permeability. In this study, metallic ferromagnetic chalcospinels are introduced into the field of single-phase DNMs, which significantly broadens the range of metamaterials. Furthermore, this study contributes to the theoretical understanding and tuning mechanism of double negative properties.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2017
·
IF 2.714
Yi-Jun Liang,Fengguo Fan,Ming Ma,Jianfei Sun,Jun Chen,Yu Zhang,Ning Gu
A great deal of effort has demonstrated magnetite nanoparticles (Fe 3 O 4 NPs) are important subject applied in tumor hyperthermia due to their excellent magneto-thermal effect. Our previous study had ultrafast prepared 6nm Fe 3 O 4 NPs via microwave approach and found that these small size NPs are responsible for microwave energy conversion to accelerate NPs formation. Hence, we suppose that investigating the size-dependent behavior of Fe 3 O 4 NPs should be beneficial for developing their electromagnetic energy conversion application for hyperthermia. In this study, Fe 3 O 4 NPs with four sizes (i.e. 4nm, 20nm, 50nm and 200nm) were prepared by a rapid microwave synthetic strategy. The specific absorption rate (SAR) value and reflection loss (RL) value of samples were investigated by measuring the time-dependent temperature curves in alternating magnetic field (AMF, 390 and 780kHz, 12A) and via vector network analyzer (VNA) range from 2 to 18GHz, respectively. Results indicated that using magnetic induction hyperthermia frequency Fe 3 O 4 NPs with single domain size of 20nm possess maximum, whereas the RL value increases with the size at microwave frequency. More importantly, the frequency of maximum RL value was matched with the clinical microwave hyperthermia. We subsequently introduce the micromagnetic (OOMMF) simulation to help understanding the issue due to the fundamental importance of size effect for magnetic NPs in energy conversion. Simulation results suggested that coupling interaction and magnetic dipole-dipole interaction between magnetic NPs and electromagnetic field would be seen as synergistic effect to impact absorption behavior, and we believe that this work can provide a valuable reference for size selection of magnetic nanoparticles in clinical application of hyperthermia.
研究领域:
材料科学
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生物医学工程
·
纳米技术
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DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
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2020
·
IF 6.444
Guohua Fan,Zhongyang Wang,Zaixin Wei,Yao Liu,Runhua Fan
Materials with negative permittivity have attracted considerable attention due to their promising applications in various electromagnetic equipment and electronic devices. Herein, percolative nickel/rutile cermets were sintered, of which the dielectric and magnetic properties were investigated in radio-frequency region. With nickel content increasing, electrical conductivity of the percolative cermets increased dramatically and the conduction mechanism changed from hopping to metallic behavior. Enhancement of positive permittivity in the percolating cermets was attributed to the increased interfacial polarization, while negative permittivity of the percolated cermets with nickel content exceeding percolation threshold was caused by plasma oscillation of delocalized electrons. Meanwhile, magnetic permeability of the epsilon-negative cermets was smaller than 1, which was resulted from the induced high-frequency diamagnetic response of eddy currents within the interconnected conductive networks. This work elucidated the anomalous dielectric and magnetic properties of percolated cermets and determined diamagnetism is an inherent nature of epsilon-negative metacomposites at high frequency.
研究领域:
材料科学
·
电磁学
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DOI
高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 36
·e202203100
·
IF 2.307
Yanhong Wang,Duming Gong,Hongcheng Lu
Graphical Two new three-dimensional coordination polymers based on same semi-flexible ligand 1,4-bis(imidazole-1-ylmethyl)benzene (bix) have been successfully synthesized under hydrothermal condition. Both of them have similar local coordination environments but different magnetic properties due to their different topological structures and spin number S . Two new coordination polymers Ni(bix) 3 ⋅ 2(NO 3 ) ⋅ (H 2 O) 1 and Co(bix) 2 ⋅ 2(NO 3 ) 2 (bix=1,4-bis(imidazole-1-ylmethyl)benzene) have successfully been synthesized via hydrothermal reactions. These two compounds have similar local coordination environments but different topological networks due to the flexibility of the bix ligand. Additionally, magnetic studies reveal that 1 and 2 also exhibit different magnetic behaviors. Although magnetic exchange pathways are same as M II -bix-M II (M=Ni 1 , Co 2 ), 1 shows purely paramagnetic state almost down to 2 K with weak antiferromagnetic interaction; while stronger antiferromagnetic interaction in 2 is suggested. Meanwhile, an anomaly around 38 K in zero-field-cooled mode is observed but suppressed in field-cooled mode, which may be suggesting the spin canting for 2 . The field dependent magnetizations show magnetization of 2.17 μ B and 2.44 μ B at 7 T for 1 and 2 , respectively. Also, the magnetic interaction J / k B of −3.3 K is estimated for 2 .
研究领域:
化学
·
材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）