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The demagnetizing field, also called the stray field (outside the magnet), is the magnetic field (H-field) [1] generated by the magnetization in a magnet.The total magnetic field in a region containing magnets is the sum of the demagnetizing fields of the magnets and the magnetic field due to any free currents or displacement currents.
The NRM is then stripped away in a stepwise manner using thermal or alternating field demagnetization techniques to reveal the stable magnetic component. Magnetic orientations of all samples from a site are then compared and their average magnetic polarity is determined with directional statistics , most commonly Fisher statistics or ...
Coils in the probe are periodically charged by current pulses and thus generate a magnetic field. On the surface of any electrically conductive material which is in the magnetic field eddy currents are produced. They induce a magnetic field in opposite directions. The resulting change in voltage can be utilized for the measurement.
Paramagnetic materials have a weak induced magnetization in a magnetic field, which disappears when the magnetic field is removed. Ferromagnetic and ferrimagnetic materials have strong magnetization in a magnetic field, and can be magnetized to have magnetization in the absence of an external field, becoming a permanent magnet. Magnetization is ...
Magnetic hysteresis can be characterized in various ways. In general, the magnetic material is placed in a varying applied H field, as induced by an electromagnet, and the resulting magnetic flux density (B field) is measured, generally by the inductive electromotive force introduced on a pickup coil nearby the sample.
Magnetic yoke is a hand-held device that induces a magnetic field between two poles. Common applications are for outdoor use, remote locations, and weld inspection. The drawback of magnetic yokes is that they only induce a magnetic field between the poles, so large-scale inspections using the device can be time-consuming.
By choosing a magnetic material with a high (BH) max, and also choosing the aspect ratio of the magnet so that its −BH is equal to (BH) max, the required volume of magnet to achieve a target flux density in the air gap is minimized. This expression assumes that the permeability in the core that is connecting the magnetic material to the air ...
The magnetic anisotropy of a benzene ring (A), alkene (B), carbonyl (C), alkyne (D), and a more complex molecule (E) are shown in the figure. Each of these unsaturated functional groups (A-D) create a tiny magnetic field and hence some local anisotropic regions (shown as cones) in which the shielding effects and the chemical shifts are unusual.