Diamagnetism

MANYETİZMA
Manyetizmanın Tarihi
Manyetizmanın Tanımı
Mıknatıslanmanın Tanımı
Doyma Mıknatıslanması
Manyetik Bölgeler
MANYETİZMA ÇEŞİTLERİ
Paramanyetizma
Diyamanyetizma
Ferromanyetizma
Antiferromanyetizma
Ferrimanyetizma
MANYETİK ALINGANLIK
Manyetik Alınganlığın Tanımı
Manyetik Alınganlık Ölçüm Yöntemi
Manyetik Alınganlık Ölçüm Sistemi

Magnetic susceptibility is a measure of how much a material will become magnetized in an applied magnetic field. Magnetic susceptibility, X is a ratio of magnetization, M to the magnetic field intensity, H. X > 0 is paramagnetism, and X < 0 is diamagnetism. The objective of the experiment is to determine the magnetic susceptibilities of FeCl_3 solution and water. The volume and mass susceptibilities of the solution are also determined. The experiment consists of two parts. The first part is to measure the magnetic flux as a function of the current. The second part is to measure the change in the liquid column as a function of current. The best value for magnetic flux is obtained at I = 0 A. For series connection, Φ0 = (1.54 ± 0.01) x 10-6 mWb. For parallel connection, Φ0 = [(1.61 x 10-6) ± (3.18 x 10-4)] mWb. It is obtained that FeCl_3 is paramagnetic and water is diamagnetic. In particular, for FeCl_3, X = 0.04 ± (6.76 x 10-6). Whereas, for water, X = - (1.9 ± 7.0) x 10-3. The volume and mass susceptibilities of FeCl_3 are only managed to be simplified algebraically.

A Horizontal Diamagnetic Levitation Based Low Frequency Vibration Energy Harvester This paper investigates a horizontal diamagnetic levitation (HDL) system for vibration energy harvesting in contrast to the vertical diamagnetic levitation (VDL) system recently proposed by Wang et al. (2013, " A Magnetically Levitated Vibration Energy Harvester, " Smart Mater. Struct., 22(5), p. 055016). In this configuration, two large magnets, alias lifting magnets (LMs), are arranged co-axially at a distance such that in between them a magnet, alias floating magnet (FM), is passively levitated at a laterally offset equilibrium position. The levitation is stabilized in the horizontal direction by two diamagnetic plates (DPs) made of pyrolytic graphite placed on each side of the FM. This HDL configuration mitigates the limitation on the amplitude of the FM imposed in the VDL configuration and exploits the ability to tailor the geometry to meet specific applications due to its frequency tuning capability. A simple circular coil geometry is designed to replace a portion of the pyrolytic graphite plate without sacrificing the stability of the levitation for trans-duction. An experimental setup exhibits a weak softening frequency response and validates the theoretical findings; at an input root mean square (RMS) acceleration of 0.0434 m/s 2 and at a resonant frequency of 1.2 Hz, the prototype generated a RMS power of 3.6 lW with an average system efficiency of 1.93%.

This article identifies and studies key parameters that characterize a horizontal diamagnetic levitation mechanism–based low frequency vibration energy harvester with the aim of enhancing performance metrics such as efficiency and volume figure of merit. The horizontal diamagnetic levitation mechanism comprises three permanent magnets and two diamag-netic plates. Two of the magnets, lifting magnets, are placed co-axially at a distance such that each attracts a centrally located magnet, floating magnet, to balance its weight. This floating magnet is flanked closely by two diamagnetic plates which stabilize the levitation in the axial direction. The influence of the geometry of the floating magnet, the lifting magnet , and the diamagnetic plate is parametrically studied to quantify their effects on the size, stability of the levitation mechanism, and the resonant frequency of the floating magnet. For vibration energy harvesting using the horizontal dia-magnetic levitation mechanism, a coil geometry and eddy current damping are critically discussed. Based on the analysis, an efficient experimental system is setup which showed a softening frequency response with an average system efficiency of 25.8% and a volume figure of merit of 0.23% when excited at a root mean square acceleration of 0.0546 m/s 2 and at a frequency of 1.9 Hz.

Magneto-optical properties are wide and span various applications such as magnetic field sensing, imaging technologies, security encoding... In this work, we have revisited the all-optical Inverse Faraday effect method to measure the Faraday rotation angle and determine the Verdet constant of diamagnetic/paramagnetic liquid solutions. We show that using a picosecond laser source the Inverse Faraday effect enables to reach magnetic flux densities in liquids in the range of 1-100 T with average power ranging below 10 mW, levels which are comparable or higher than those obtained using electromagnets to generate pulsed magnetic fields. This all-optical method with no pump-probe scheme has the advantage that it requires small volumes (&lt;100 µl) and enables in situ fast and efficient static measurements. We further show it is possible to determine the Verdet constant of solutes in binary diluted solutions and we also emphasize that chiral molecules exhibit considerable enantiomeric diff...

ABSTRACTThe induced magnetic moment of a biased semiconductor tunnel-coupled parallel double quantum wire system is examined here. The wires are in a series arrangement with tunnel coupling to each other and to leads. Their parallel lengths and associated continuous spectrum are taken in the direction perpendicular to the lead-to-lead current. The equations of motion for the double-wire electron Green&#39;s function are formulated and analyzed using the transfer-tunneling Hamiltonian formalism. We determine the average magnetic moment of the double-wire system induced by a magnetic field applied perpendicular to the plane of the structure and we show that there are crossovers between diamagnetic and paramagnetic behavior, depending on the bias voltage, equilibrium chemical potential of the leads and temperature.

A crystal engineering approach is used to stabilize a radical anion in the crystalline state and to modulate the separation distance within π-stacks of anion radicals. Alkali metal salts of 2,3-dicyano-5,6-dichlorosemiquinone (C8Cl2N2O2, DDQ∙- radical anions were prepared and their crystal structures determined: LiDDQ·2H2O·(CH3)2CO, RbDDQ·2H2O and CsDDQ·2H2O. In these structures, stacked dimers of radical anions are formed within π-stacked columns. Within the stacked dimers, interplanar separation distances are significantly shorter than the sum of the van der Waals radii for two C atoms; the shortest is 2.812 Å for the Li salt and the longest is 2.925 Å for the Cs salt. Diamagnetic character, observed by electron paramagnetic resonance spectroscopy, indicates spin-coupling of the unpaired electrons within the radical anion dimer. The electron-rich cyano substituents on DDQ∙- influence the electron redistribution within the ring skeleton. The crystalline compounds are also character...