Exchange

class micromagneticmodel.Exchange(**kwargs)

Exchange energy term.

\[w = - A \mathbf{m} \cdot \nabla^{2} \mathbf{m}\]

Parameters:

A (numbers.Real, dict, discretisedfield.Field) – If a single unsigned value numbers.Real is passed, a spatially constant parameter is defined. For a spatially varying parameter, either a dictionary, e.g. A={'region1': 1e-12, 'region2': 5e-12} (if the parameter is defined “per region”) or discretisedfield.Field is passed.

Examples

1. Defining the exchange energy term using scalar.

>>> import micromagneticmodel as mm
...
>>> exchange = mm.Exchange(A=1e-12)

2. Defining the exchange energy term using dictionary.

>>> exchange = mm.Exchange(A={'region1': 1e-12, 'region2': 2e-12})

3. Defining the exchange energy term using discretisedfield.Field.

>>> import discretisedfield as df
...
>>> region = df.Region(p1=(0, 0, 0), p2=(5e-9, 5e-9, 5e-9))
>>> mesh = df.Mesh(region=region, n=(5, 5, 5))
>>> A = df.Field(mesh, nvdim=1, value=5e-11)
>>> exchange = mm.Exchange(A=A)

4. An attempt to define the exchange energy term using a wrong value.

>>> exchange = mm.Exchange(A='123')  # string value
Traceback (most recent call last):
...
TypeError: ...

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Methods

__add__	Binary + operator.
__dir__	Default dir() implementation.
__eq__	Relational operator ==.
__iter__	Iterator.
__repr__	Representation string.
density
effective_field
energy

Properties

A	Descriptor allowing setting attributes with a value described as descriptor or a dictionary.
name	Name.

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