`exspy.material`#

`atomic_to_weight`(atomic_percent[, elements])	Convert atomic percent to weight percent.
`density_of_mixture`(weight_percent[, ...])	Calculate the density of a mixture of elements.
`elements`	Database of element properties.
`mass_absorption_coefficient`(element, energies)	Mass absorption coefficient (mu/rho) of a X-ray absorbed in a pure material.
`mass_absorption_mixture`(weight_percent[, ...])	Calculate the mass absorption coefficient for X-ray absorbed in a mixture of elements.
`weight_to_atomic`(weight_percent[, elements])	Convert weight percent (wt%) to atomic percent (at.%).

exspy.material.atomic_to_weight(atomic_percent, elements='auto')#

Convert atomic percent to weight percent.

Parameters:

atomic_percent (list of float or list of signals) – The atomic fractions (composition) of the sample.
elements (list of str) – A list of element abbreviations, e.g. [‘Al’,’Zn’]. If elements is ‘auto’, take the elements in en each signal metadata of the atomic_percent list.

Returns:

weight_percent – Composition in weight percent.

Return type:

numpy.ndarray of float

Examples

Calculate the weight percent of modern bronze given its atomic percent:

>>> exspy.material.atomic_to_weight([93.2, 6.8], ("Cu", "Sn"))
array([ 88.00501989,  11.99498011])

See also

exspy.material.weight_to_atomic

exspy.material.density_of_mixture(weight_percent, elements='auto', mean='harmonic')#

Calculate the density of a mixture of elements.

The density of the elements is retrieved from an internal database. The calculation is only valid if there is no interaction between the components.

Parameters:

weight_percent (list of float or list of signals) – A list of weight percent for the different elements. If the total is not equal to 100, each weight percent is divided by the sum of the list (normalization).
elements (list of str) – A list of element symbols, e.g. [‘Al’, ‘Zn’]. If elements is ‘auto’, take the elements in en each signal metadata of the weight_percent list.
mean ('harmonic' or 'weighted') – The type of mean use to estimate the density. Default is 'harmonic'.

Returns:

density – The density in g/cm3.

Return type:

numpy.ndarray of float or hyperspy.api.signals.BaseSignal

Examples

Calculate the density of modern bronze given its weight percent:

>>> exspy.material.density_of_mixture([88, 12],['Cu', 'Sn'])
8.6903187973131466

exspy.material.mass_absorption_coefficient(element, energies)#

Mass absorption coefficient (mu/rho) of a X-ray absorbed in a pure material.

The mass absorption is retrieved from the database of Chantler et al. [*].

Parameters:

element (str) – The element symbol of the absorber, e.g. ‘Al’.
energies (float or list of float or str or list of str) – The energy or energies of the X-ray in keV, or the name of the X-rays, e.g. ‘Al_Ka’.

Returns:

mass_absorption_coefficients – Mass absorption coefficient(s) in cm^2/g

Return type:

numpy.ndarray of float

Examples

>>> exspy.material.mass_absorption_coefficient(
>>>     element='Al', energies=['C_Ka','Al_Ka'])
array([ 26330.38933818,    372.02616732])

References

exspy.material.mass_absorption_mixture(weight_percent, elements='auto', energies='auto')#

Calculate the mass absorption coefficient for X-ray absorbed in a mixture of elements.

The mass absorption coefficient is calculated as a weighted mean of the weight percent and is retrieved from the database of Chantler et al. [†].

Parameters:

weight_percent (list of float or list of signals) – The composition of the absorber(s) in weight percent. The first dimension of the matrix corresponds to the elements.
elements (list of str or 'auto') – The list of element symbol of the absorber, e.g. [‘Al’,’Zn’]. If elements is ‘auto’, take the elements in each signal metadata of the weight_percent list.
energies (list of float or list of str or 'auto') – The energy or energies of the X-ray in keV, or the name of the X-rays, e.g. ‘Al_Ka’. If ‘auto’, take the lines in each signal metadata of the weight_percent list.

Examples

>>> exspy.material.mass_absorption_mixture(
>>>     elements=['Al','Zn'], weight_percent=[50,50], energies='Al_Ka')
2587.41616439

Returns:: mass_absorption_coefficient – The Mass absorption coefficient(s) of the mixture in cm^2/g
Return type:: numpy.ndarray of float or hyperspy.api.signals.BaseSignal

References

exspy.material.weight_to_atomic(weight_percent, elements='auto')#

Convert weight percent (wt%) to atomic percent (at.%).

Parameters:

weight_percent (list of float or list of signals) – The weight fractions (composition) of the sample.
elements (list of str) – A list of element abbreviations, e.g. [‘Al’,’Zn’]. If elements is ‘auto’, take the elements in en each signal metadata of th weight_percent list.

Returns:

atomic_percent – Composition in atomic percent.

Return type:

numpy.ndarray of float

Examples

Calculate the atomic percent of modern bronze given its weight percent:

>>> exspy.material.weight_to_atomic((88, 12), ("Cu", "Sn"))
array([ 93.19698614,   6.80301386])

See also

exspy.material.atomic_to_weight

material.elements#

Database of element properties.

The following properties are included:

├── Atomic_properties
│   ├── Binding_energies
│   └── Xray_lines
├── General_properties
│   ├── Z
│   ├── atomic_weight
│   └── name
└── Physical_properties
    └── density_gcm3

The X-ray lines energies are taken from Chantler et al. [1].

The line weight, more precisely the approximate line weight for K, L, M shells are taken from the Electron Probe Quantification (EPQ) library [2].

The field threshold and edge are taken from the Gatan EELS atlas https://eels.info/atlas, as retrieved in June 2020.

Examples

>>> exspy.material.elements.Fe.General_properties
├── Z = 26
├── atomic_weight = 55.845
└── name = iron
>>> exspy.material.elements.Fe.Physical_properties
└── density (g/cm^3) = 7.874
>>> exspy.material.elements.Fe.Atomic_properties.Xray_lines
├── Ka
│   ├── energy (keV) = 6.404
│   └── weight = 1.0
├── Kb
│   ├── energy (keV) = 7.0568
│   └── weight = 0.1272
├── La
│   ├── energy (keV) = 0.705
│   └── weight = 1.0
├── Lb3
│   ├── energy (keV) = 0.792
│   └── weight = 0.02448
├── Ll
│   ├── energy (keV) = 0.615
│   └── weight = 0.3086
└── Ln
    ├── energy (keV) = 0.62799
    └── weight = 0.12525

References

exspy.material#

`exspy.material`#