MagnetoElastic#

class micromagneticmodel.MagnetoElastic(**kwargs)#

Magneto-elastic energy term.

\[w = B_{1}\sum_{i} m_{i}\epsilon_{ii} + B_{2}\sum_{i}\sum_{j\ne i} m_{i}m_{j}\epsilon_{ij}\]
Parameters:

  • B1 (numbers.Real, dict, discretisedfield.Field) – If a single value numbers.Real is passed, a spatially constant parameter is defined. For a spatially varying parameter, either a dictionary, e.g. B1={'region1': 1e7, 'region2': 5e7} (if the parameter is defined “per region”) or discretisedfield.Field is passed.

  • B2 (numbers.Real, dict, discretisedfield.Field) – If a single value numbers.Real is passed, a spatially constant parameter is defined. For a spatially varying parameter, either a dictionary, e.g. B1={'region1': 1e7, 'region2': 5e7} (if the parameter is defined “per region”) or discretisedfield.Field is passed.

  • e_diag/e_offdiag ((3,) array_like, dict, discretisedfield.Field) –

    Symmetric strain matrix is assembled from the values of the vector e, so that eps11 = e_diag[0], eps22=e_diag[1], eps33=e_diag[2], eps23=eps32=e_offdiag[0], eps13=eps31=e_offdiag[1], eps12=eps21=e_offdiag[2].

    If a single length-3 array_like (tuple, list, numpy.ndarray) is passed, which consists of numbers.Real, a spatially constant parameter is defined. For a spatially varying parameter, either a dictionary, e.g. e={'region1': (1, 1, 1), 'region2': (1, 1, 1)} (if the parameter is defined “per region”) or discretisedfield.Field is passed.

Examples

  1. Defining the magneto-elastic energy term using single values.

>>> import micromagneticmodel as mm
...
>>> mel = mm.MagnetoElastic(B1=1e7, B2=1e7, e_diag=(1, 1, 1),
...                         e_offdiag=(0, 0, 0))

  1. Defining the magneto-elastic energy term using dictionary.

>>> B1 = B2 = {'region1': 1e7, 'region2': 2e7}
>>> e_diag = {'region1': (1, 1, 1), 'region2': (2, 2, 2)}
>>> e_offdiag = {'region1': (0, 0, 0), 'region2': (0, 0, 0)}
>>> mel = mm.MagnetoElastic(B1=B1, B2=B2, e_diag=e_diag,
...                         e_offdiag=e_offdiag)

3. Defining the magneto-elastic 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))
>>> B1 = B2 = df.Field(mesh, nvdim=1, value=1e6)
>>> e_diag = df.Field(mesh, nvdim=3, value=(1, 1, 1))
>>> mel = mm.MagnetoElastic(B1=B1, B2=B2, e_diag=e_diag,
...                         e_offdiag=(0, 0, 0))

4. An attempt to define the magneto-elastic energy term using a wrong value.

>>> # length-3 e value
>>> mel = mm.MagnetoElastic(B1=1e7, B2=2e7, e_diag=(1, 1, 1, 1))
Traceback (most recent call last):
...
ValueError: ...

Methods

__add__

Binary + operator.

__dir__

Default dir() implementation.

__eq__

Relational operator ==.

__iter__

Iterator.

__repr__

Representation string.

density

effective_field

energy

Properties

B1

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

B2

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

e_diag

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

e_offdiag

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

name

Name.