Demagnetising field

The maximum coercivity corresponds to but refers to the external field. It expHcidy takes into account the self-demagnetising field of the... 

Fig. 9. The relation of an LMR and PMR transition (a) initial state of magneti2ation (b) the magnetisation and corresponding demagnetisation fields of a ...

The anisotropy field B i and the demagnetising field Bd arise, respectively, from the last two terms of (2). These fields bring about an angular dependence of the spectra. In the cubic and axial symmetry,... 

Ho is the value of the magnetic field at the nucleus generated by an external magnet and is effectively zero away from a large magnet. The next term, —DM, is the demagnetising field and fttM is the Lorentz field (the coefficient being strictly applicable for cubic symmetry only) but both are small. arises as a result of the interaction of the nucleus with an imbalance in the s-electron spin density at the nucleus, and can be written as... 

The magnetic field H actually acting on a sample of definite geometrical shape consists of two contributions the applied external field Ha and the demagnetising field H ... 

Fig. 2.5. Demagnetising field (a) in a bar (long needle) (b) in a cylinder (c) in a slab (thin film).

Fig. 4.56. Irreversible magnetisation process. After application and removal of a strong field, the sample is in the remanence, however, due to the demagnetising field. Hi. induction decreases to the Ba value. Operation point is P.

The ferrite inductors are shaped as pot cores. Fig. 5.7, formed of two matching halves. The central part is shorter than the outer surfaces when they are in contact, a gap appears in the centre of the device. This central part has a hole, such that a magnetic rod can be inserted into it, in an adjustable position. An adjustable gap is quite useful in pot cores in addition to allowing a fine calibration of the final inductance value of the device, it decreases its temperature sensitivity and increases the working frequency. The presence of a gap leads to a lower permeability value because a demagnetising field is generated, decreasing the value of the total applied field ... 

The dipolar interactions are responsible for the energy of the demagnetision field. The minimization of this energy leads to the form effect, which is always small (<10 ). 

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