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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 default definition of magnetic remanence is the magnetization remaining in zero field after a large magnetic field is applied (enough to achieve saturation). [1] The effect of a magnetic hysteresis loop is measured using instruments such as a vibrating sample magnetometer ; and the zero-field intercept is a measure of the remanence.
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.
The magnetization field or M-field can be defined according to the following equation: = Where d m {\displaystyle \mathrm {d} \mathbf {m} } is the elementary magnetic moment and d V {\displaystyle \mathrm {d} V} is the volume element ; in other words, the M -field is the distribution of magnetic moments in the region or manifold concerned.
The alternating magnetic field induces an electric field in the pickup coils of the VSM. [4] The current is proportional to the magnetization of the sample - the greater the induced current, the greater the magnetization. As a result, typically a hysteresis curve will be recorded [5] and from there the magnetic properties of the sample can be ...
Equivalent definitions for coercivities in terms of the magnetization-vs-field (M-H) curve, for the same magnet. Coercivity in a ferromagnetic material is the intensity of the applied magnetic field (H field) required to demagnetize that material, after the magnetization of the sample has been driven to saturation by a strong field. This ...
Calibration removes the need to know the density of the sample. Variable temperature measurements can be made by placing the sample in a cryostat between the pole pieces of the magnet. [1] The Evans balance. [2] is a torsion balance which uses a sample in a fixed position and a variable secondary magnet to bring the magnets back to their ...
Adiabatic demagnetization: The substance is returned to another adiabatic (insulated) condition so the total entropy remains constant. However, this time the magnetic field is decreased, the thermal energy causes the magnetic moments to overcome the field, and thus the sample cools, i.e., an adiabatic temperature change.