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Isotropic Magnets:
it is material of a magnet whose magnetic properties are the same in any direction. They can be therefore magnetised in any direction without loss of magnetic characteristics.
Anisotropic Magnet:
it is a magnet that has a favourite direction of magnetic orientation, so that the magnetic characteristics are optimal in that direction.
Induction, B:
it is the magnetic flux for a normal sector of a normal section to the flux direction. The induction unity is Gauss in the GCS system.
Intrinsic Coercive Force, Hci:
it is an intrinsic capacity of a material to resist the demagnetization. Its value is measured in Oersted and it is correspondent to null intrinsic induction of the material after the saturation. The permanent magnets with the high intrinsic coercive force are usually associated with a high stability of temperature.
Residual Induction, Br:
it is the value of the induction in a point of the hysteresis loop, to whom the hysteresis wrap crosses up, the one of the B axis to zero that magnetizes the force. The Br is the product of the maximum magnetic flux density of this material without an external magnetic field.
Remainder, Bd:
it is the magnetic induction that remains in a magnetic circuit after the removal of an application, magnetizing the force. If there is an aerial difference in the circuit, the remainder will be lower than the remaining induction, Br.
Maximum Energy Product, (BH) max:
there is a point in the hysteresis loop where the product magnetizes the H force and the B induction reaching a maximum. The maximum value is called the Maximum Energy Product. This point is the magnet required value to program an energy. This parameter is usually used to describe how strong this permanent magnetic material is. Its unity is Gauss Oersted. One MGOe means 1.000.000 Gauss Oersted.
Coercive Force, Hcb:
it is the force of demagnetization, measure in Oersted, needed to reduce the B induction to zero, after the magnet has been previously taken to saturation.
Gauss, Gs:
it is the density unity of magnetic flux of the GSC system, the magnetic flux line per aligned inch. The induction unity is Gauss in the GCS system.
Oersted, Oe:
it is an unity to magnetize the force in the GCS system. One Oersted is equal to 79.58 A/m in HE system.
Curie Temperature:
it is the temperature at which the magnets are not able to keep magnetization anymore.
Magnetic Force:
it is the magnetomotive force for length of an unity in any point of a magnetic circuit. Oersted unity is the magnetic force of the GCS system.
Flux:
it is the condition that exists in a magnetized and undergone to a force piece. This is characterised by the fact that the electromotive force is produced in a direction that surrounds the flux at every moment.
Hysteresis Curve:
it is a one sluice curve obtained by a material, tracing and corresponding the magnetic induction value, B (on the abscissa), against the force magnetization, H (on the ordinate) = (BH)max
Irreversible loss:
it is defined as a magnet partial demagnetization caused by external causes or other reasons. These loss can be recovered only by remagnetisation. The magnet can be stabilised to avoid performance variations caused by irreversible losses.
Saturation:
it is a condition for which the induction of a ferromagnetic material has reached its maximum value with the applied increase, magnetizing the force. All the magnetic flux are oriented in one direction to the state of saturation.
Stability:
it is the capacity to resist a demagnetization during an operation. This influence of demagnetisation can be caused by high or low temperatures or by external magnetic fields
Note £º A magnet after saturation will amplify its outer magnetic field, thus the magnetic induction force will also be increased, and here we name the increased force as Bi. The curve that describes Bi-H relationships is called an intrinsic demagnetization curve.
The energy product (BH)max results from the largest rectangle to be drawn inside of the demagnetization curve. The higher the product is, the more ¡°energy¡± is stored in the magnet.
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