# Function Materials

Function materials describe a family of Moose material classes that are derived from the FunctionMaterialBase base class. A function material provides a Real material property that hold the value of an arbitrary function expression. A derivative function material in addition provides further material properties that hold the value of the derivatives of the function expression with respect to each coupled variable up to a defined derivative_order.

Available function materials are

MaterialDescription
ParsedMaterialSets up a single material property that is computed using a parsed function expression
DerivativeParsedMaterialExtends ParsedMaterial and provides the automatically generated derivatives of the function expression w.r.t. all coupled variables.
DerivativeSumMaterialCreate new material properties that contain the sum of multiple function material properties (including the sums of the derivatives)
ElasticEnergyMaterialGenerates an elastic free energy function material from the current stress/strain state including necessary derivatives
SwitchingFunctionMaterialA convenience material to generate a soft switching function used in multiphase modeling
BarrierFunctionMaterialA convenience material to generate a barrier function used in multiphase modeling
MathFreeEnergyA simple double-well free energy (and its concentration derivatives)