MAGNETIC NANOCHAINS: A REVIEW

NANO ◽  
2011 ◽  
Vol 06 (01) ◽  
pp. 1-17 ◽  
Author(s):  
HUI WANG ◽  
YIFEI YU ◽  
YUBIN SUN ◽  
QIANWANG CHEN
Keyword(s):  
Magnetic Field ◽  
Self Assembly ◽  
Magnetic Interactions ◽  
Synthesis Methods ◽  
Zero Field ◽  
Magnetic Recording Media ◽  
1D Chain ◽  
Potential Applications ◽  
Micromechanical Sensors ◽  
Nanoparticle Chains

One-dimensional (1D) chain-like structures are of special significance because of their interparticle magnetic interactions and potential applications in various fields, such as micromechanical sensors. This paper attempts to review the field of research into magnetic chains including monatomic chains and nanoparticle chains. The synthesis methods used mostly belong to one of the following categories: magnetosome chains in magnetotactic bacteria, zero-field self-assembly, magnetic field induced (MFI) assembly, template-directed synthesis, and gas phase synthesis. The potential applications of nanoparticle chains, mainly in the field of magnetic recording media, sensor, biomedicine and magnetic-field tunable photonic crystal are discussed.

VORTEX MAGNETISM IN THE HIGH-TEMPERATURES SUPERCONDUCTOR La2-xSrxCuO4

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3155-3155
Author(s):  
B. LAKE ◽  
T. E. MASON ◽  
G. AEPPLI ◽  
K. LEFMANN ◽  
N. B. CHRISTENSEN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Normal State ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Field Measurements ◽  
Spin Fluctuations ◽  
Magnetic Interactions ◽  
Zero Field ◽  
Zero Resistance ◽  
Lower Temperature

There is strong evidence that magnetic interactions play a crucial role in the mechanism driving high-temperature superconductivity in cuprate superconductors. To investigate this further we have done a series of neutron scattering measurements on La 2-x Sr x CuO 4 (LSCO) in an applied magnetic field. Below Tc the field penetrates the superconductor via an array of normal state metallic inclusions or vortices. Phase coherent superconductivity characterized by zero resistance sets in at the lower field-dependent irreversibility temperature (Tirr). We have measured optimally doped LSCO (x = 0.16, Tc = 38.5 K ) and underdoped LSCO (x = 0.10, Tc = 29 K ); both have an enhanced antiferromagnetic response in a field. Measurements of the optimally doped system at H = 7.5 T show that sub-gap spin fluctuations first disappear with the loss of finite resistivity at Tirr, but then reappear at a lower temperature with increased lifetime and correlation length compared to the normal state. In the underdoped system elastic antiferromagnetism develops below Tc in zero field, and is significantly enhanced by application of a magnetic field. Phase coherent superconductivity is then established within the antiferromagnetic phase at Tirr; thus, the situation in underdoped LSCO is the reverse of that for the optimally doped LSCO where the zero-resistance state develops first before the onset of antiferromagnetism.

Synthesis, crystal structure and magnetic properties of a one-dimensional Mn2+ complex constructed from (+)-dibenzoyltartaric acid and 2,2′-bipyridine

2021 ◽  
Vol 77 (11) ◽  
Author(s):  
Yuan Jiao ◽  
Fu-Ning Jin ◽  
Si-Si Feng ◽  
Ai Wang ◽  
Ulli Englert
Keyword(s):  
Magnetic Properties ◽  
Self Assembly ◽  
Zero Field ◽  
X Ray Diffraction ◽  
Zero Field Splitting ◽  
Orthorhombic Space Group ◽  
Distorted Octahedral ◽  
1D Chain ◽  
Coordinated Water ◽  
Thermal Stability Of

The self-assembly reaction of (+)-dibenzoyltartaric acid (D-H2DBTA) with 2,2′-bipyridine (bpy) and Mn(CH3CO2)2·4H2O yielded a new coordination polymer, namely, catena-poly[[[diaqua(2,2′-bipyridine-κ2 N,N′)manganese(II)]-μ-2,3-bis(benzoyloxy)butanedioato-κ2 O 2:O 3] dihydrate], {[Mn(C18H12O8)(C10H8N2)(H2O)2]·2H2O} n or {[Mn(DBTA)(bpy)(H2O)2]·2H2O} n , (I). Complex (I) has been characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA) and single-crystal and powder X-ray diffraction. It crystallizes in the orthorhombic space group P212121. In the complex, the Mn2+ cation displays a distorted octahedral {MnO4N2} geometry, formed from two carboxylate O atoms of two DBTA2− ligands, two cis-oriented N atoms from one chelating 2,2′-bipyridine ligand and two trans-oriented O atoms from coordinated water molecules. The polymer displays a 1D chain with an Mn...Mn distance of 9.428 (1) Å. Due to the presence of flexible polycarboxylate and rigid bipyridyl ligands in the molecular structure, a high thermal stability of the complex is attained. The magnetic properties of (I) were analyzed based on the mononuclear Mn2+ model due to the long intramolecular Mn...Mn distance. The zero field splitting (ZFS) contribution in the high-spin Mn2+ cation is almost negligible and there are weak antiferromagnetic couplings between 1D chains [zJ′ = −0.062 (5) cm−1], corresponding to an intermolecular Mn...Mn distance of 7.860 (2) Å.

FIELD-INDUCED ANTIFERROMAGNETISM IN THE HIGH-TEMPERATURE SUPERCONDUCTOR La2-xSrxCuO4

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3197-3197
Author(s):  
B. LAKE ◽  
T. E. MASON ◽  
G. AEPPLI ◽  
K. LEFMANN ◽  
N. B. CHRISTENSEN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Normal State ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Field Measurements ◽  
Spin Fluctuations ◽  
Magnetic Interactions ◽  
Zero Field ◽  
Zero Resistance

There is strong evidence that magnetic interactions play a crucial role in the mechanism driving high-temperature superconductivity in cuprate superconductors. To investigate this we have done a series of neutron scattering measurements on La 2-x Sr x CuO 4 (LSCO) in an applied magnetic field. Below Tc the field penetrates the superconductor via an array of normal state metallic inclusions or vortices. Phase coherent superconductivity characterized by zero resistance sets in at the lower field-dependent irreversibility temperature (Tirr). We have measured optimally doped LSCO (x = 0.16, Tc = 38.5 K ) and under-doped LSCO ( x = 0.10, Tc = 29 K ); both have an enhanced antiferromagnetic response in a field. Measurements of the optimally doped system at H = 7.5 T show that sub-gap spin fluctuations first disappear with the loss of finite resistivity at Tirr, but then reappear at a lower temperature with increased lifetime and correlation length compared to the normal state. In the under-doped system elastic antiferromagnetism develops below Tc in zero field, and is significantly enchanced by application of a magnetic field. Phase coherent superconductivity is then established within the antiferromagnetic phase at Tirr; thus, the situation in under-doped LSCO is the reverse of that for the optimally doped LSCO where the zero-resistance state develops first before the onset of antiferromagnetism.

Digital phase analysis in interference electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 842-843
Author(s):  
S. Hasegawa ◽  
T. Kawasaki ◽  
J. Endo ◽  
M. Futamoto ◽  
A. Tonomura
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Phase Distribution ◽  
Magnetic Recording Media ◽  
Electron Wave ◽  
Vector Potentials ◽  
Weak Magnetic Fields ◽  
Leakage Magnetic Field ◽  
Optical Reconstruction ◽  
Processing Techniques

Interference electron microscopy enables us to record the phase distribution of an electron wave on a hologram. The distribution is visualized as a fringe pattern in a micrograph by optical reconstruction. The phase is affected by electromagnetic potentials; scalar and vector potentials. Therefore, the electric and magnetic field can be reduced from the recorded phase. This study analyzes a leakage magnetic field from CoCr perpendicular magnetic recording media. Since one contour fringe interval corresponds to a magnetic flux of Φo(=h/e=4x10-15Wb), we can quantitatively measure the field by counting the number of finges. Moreover, by using phase-difference amplification techniques, the sensitivity for magnetic field detection can be improved by a factor of 30, which allows the drawing of a Φo/30 fringe. This sensitivity, however, is insufficient for quantitative analysis of very weak magnetic fields such as high-density magnetic recordings. For this reason we have adopted “fringe scanning interferometry” using digital image processing techniques at the optical reconstruction stage. This method enables us to obtain subfringe information recorded in the interference pattern.

Porphyrin-functionalized coordination star polymers and their potential applications in photodynamic therapy

2019 ◽  
Vol 10 (45) ◽  
pp. 6116-6121 ◽  
Author(s):  
Tan Ji ◽  
Lei Xia ◽  
Wei Zheng ◽  
Guang-Qiang Yin ◽  
Tao Yue ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Self Assembly ◽  
Star Polymers ◽  
New Family ◽  
Potential Applications

We present a new family of porphyrin-functionalized coordination star polymers prepared through combination of coordination-driven self-assembly and post-assembly polymerization. Their self-assembly behaviour in water and potential for photodynamic therapy were demonstrated.

Computational and Experimental Binding Mechanism of DNA-drug Interactions

2019 ◽  
Vol 24 (32) ◽  
pp. 3739-3757 ◽  
Author(s):  
Chandrabose Selvaraj ◽  
Sanjeev K. Singh
Keyword(s):  
Small Molecules ◽  
Self Assembly ◽  
Genetic Material ◽  
Dna Interaction ◽  
Significant Feature ◽  
Drug Molecules ◽  
Potential Applications ◽  
Novel Drug ◽  
Groove Binders ◽  
Molecular Docking And Dynamics

Nucleic acid is the key unit and a predominant genetic material for interpreting the fundamental basis of genetic information in an organism and now it is used for the evolution of a novel group of therapeutics. To identify the potential impact on the biological science, it receives high recognition in therapeutic applications. Due to its selective recognition of molecular targets and pathways, DNA significantly imparts tremendous specificity of action. Examining the properties of DNA holds numerous advantages in assembly, interconnects, computational elements, along with potential applications of DNA self-assembly and scaffolding include nanoelectronics, biosensors, and programmable/autonomous molecular machines. The interaction of low molecular weight, small molecules with DNA is a significant feature in pharmacology. Based on the mode of binding mechanisms, small molecules are categorized as intercalators and groove binders having a significant role in target-based drug development. The understanding mechanism of drug-DNA interaction plays an important role in the development of novel drug molecules with more effective and lesser side effects. This article attempts to outline those interactions of drug-DNA with both experimental and computational advances, including ultraviolet (UV) -visible spectroscopy, fluorescent spectroscopy, circular dichroism, nuclear magnetic resonance (NMR), molecular docking and dynamics, and quantum mechanical applications.

Nano sensors: Designing and Fabrication, Applications for flexible devices and Future Perspectives

2020 ◽  
Vol 16 ◽  
Author(s):  
Muhammad Bilal Tahir ◽  
Aleena Shoukat ◽  
Tahir Iqbal ◽  
Asma Ayub ◽  
Saff-e Awal ◽  
...  
Keyword(s):  
Self Assembly ◽  
Multidisciplinary Approach ◽  
Future Perspectives ◽  
Flexible Devices ◽  
More Care ◽  
Potential Applications ◽  
Nano Sensors ◽  
Mechanical Sensor ◽  
Small Models ◽  
Near Future

: The field of nanosensors has been gaining a lot of attention due to its properties such as mechanical and electrical ever since its first discovery by Dr. Wolter and first mechanical sensor in 1994. The rapidly growing demand of nanosensors has become profitable for a multidisciplinary approach in designing and fabrication of materials and strategies for potential applications. Frequent stimulating advancements are being suggested and established in recent years and thus heading towards multiple applications including food safety, healthcare, environmental monitoring, and biomedical research. Nanofabrication being an efficient method has been used in different industries like medical pharmaceutical for their complex functional geometry at a lower scale. These nanofabrications apply through different methods. There are five most commonly known methods which are frequently used, including top-down lithography, molecular self-assembly, bottom-up assembly, heat and pull method for fabrication of biosensors, etching for fabrication of nanosensors etc. Nanofabrication help at the nanoscale to design and work with small models. But these models due to their small size and being sensitive need more care for use as well as more training and experience to do work with. All methods used for nanofabrication are good and helpful. But more preferred is molecular self-assembly as it is helpful in mass production. Nanofabrication has become an emerging and developing field and it assumed that in near future our world is known by the new devices of nanofabrication.

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