# B(H, T) law: models

## Introduction

The models provided are available only for isotropic soft magnetic materials.

The decrease of **B(H)** characteristics with the temperature is:

- either an exponential decay
- or a decay defined by the user (table of values)

## Models for soft magnetic materials

The various models available for the description of soft magnetic materials, whose magnetization behavior is a function of the temperature, are presented in the following table.

Models for soft magnetic materials (linear approximation) | |
---|---|

Linear isotropic exponential function of T tabulated function of T |
B= μ (T).H |

Models for isotropic soft magnetic materials (nonlinear approximation) | |
---|---|

Saturation isotropic: analytic exponential function of T tabulated function of T |
B= μ (H,T).H |

Saturation isotropic: analytic + knee adjustment exponential function of T |

Specific models are also provided (see table below). Their mode of use is presented in § Spatial model / user model

Magnetic property … |
---|

… spatial linear isotropic (μ_{r} described via spatial
formula) |

… user (μ_{r} described via user subroutine and personal
version) |

## Mathematical models

The models provided for the **B(H)** curves, depending on temperature, with
exponential decay, are defined by means of:

- the previous models provided for soft materials
- the temperature coefficient
**COEF(T)**based on two exponential functions