Ferrite ceramics produce one of the strongest types of magnetics, and consist of iron, boron and barium, or strontium and molybdenum. A ferrite material is a ceramic magnet which has high magnetic permeability, which allows it to store stronger magnetic fields than iron.
Specimen preparation of friable or brittle materials such as ferrites can be difficult. Proper microstructural preparation of these materials must maintain the structure of the Ni-Fe ferrite structure. This is accomplished by mounting the ferrite in a castable mounting compound such as epoxy. Initial grinding with a 320 grit or finer SiC paper is required to prevent pulling out the ferrite particles, especially the smaller particles. Rough polishing is accomplished on woven polishing cloths using diamond, with final polishing on high napped cloth using a polycrystalline alumina abrasive.
SECTIONING
Diamond wafer cutting with medium grit / low concentration diamond blades
MOUNTING
Castable mounting acrylics or epoxies
POLISHING
Abrasive/surface |
Lubricant |
Force/ sample |
Speed |
Time |
240 grit SiC paper |
Water |
5-10 lbs |
100/100 rpm |
Until plane |
1 um DIAMAT diamond on ATLANTIS polsihing pad |
SIAMAT Colloidal Silica |
5-10 lbs |
100/100 rpm |
5 minutes |
0.05 um Nanometer alumina on NAPPAD polishing pad |
|
5-10 lbs |
100/100 rpm |
1 minutes |
 |
Ni-Zn ferrite, 400X (B.F.), as polished condition |