Anisotropic Magnetoresistance

Hi!

I need to simulate an AMR sensor, which is a magnetometer, whose working principle is based on the Anisotropic Magnetoresistance. The sensor is made of a thin strip of permalloy, a ferromagnetic material, with its typical hysteretic behaviour (M-H curve). The material is anisotropic, which means that its behaviour depends on the direction of the external Magnetic Field H. Due to this Magnetic Field H, the Magnetization Vector M rotates. The resistivity of the sensor depends of the angle between the Current I flowing through the sensor and the Magnetization Vector M.

First problems are:
- How to define the material (it's not included into the Material Library). Is there in the Material Library any similar material with the same properties? How can I insert my M-H curve (with hysteresis) into the model from data?
- How can I define an intrinsic Magnetization Vector M of the material?
- Which is the proper model to describe this sensor? I think it's the Magnetic Fields No Currents one, but I'm not sure.

The main problem is:
- How can I get the rotation of the Magnetization Vector M?

Thank you!
Paolo