Domain and domain wall transition spectroscopy

A process for testing of a sample of magnetic material to determine the magnetic domain and domain wall spectra of said sample comprising the steps of:

• providing a magnetic sample having a certain magnetization, anisotropy, coercivity, and geometry;
• providing an adjustable resonant cavity into which high frequency radiation with a magnetic field along a first axis of said cavity is introduced;
• providing an adjustable high frequency source communicated to said adjustable resonant cavity;
• providing an adjustable quasi-static magnetic field communicated across said cavity, said adjustable quasi-static field being disposed at an angle to the magnetic field induced by said high frequency radiation in said adjustable cavity;
• computing the resonant frequency of said sample at a magnetic field H equal to the coercive force H.sub.c in said cavity as function of the magnetization of said sample, the anisotropy of said sample, the geometry of said sample;
• adjusting said adjustable resonant cavity to resonate at said computed resonant frequency of said sample;
• adjusting said adjustable high frequency source to said adjustable cavity resonance frequency, as well as to said resonance frequency of said sample in said cavity;
• plotting the power output from the cavity as a function of the quasi-static magnetic field H applied to the sample in the cavity to determine the magnetic transitions of the sample at a quasi-static magnetic field H nearly equal to the coercivity of the sample.