What kind of magnetic core is best?
There is no answer to this question because the choice of core is determined by the occasion and the frequency of application. Any material selection must consider factors such as market. For example, some materials can guarantee a small temperature rise, but It is expensive, so that when materials are selected for higher temperature rises, it is possible to select larger size with lower priced materials to accomplish such work.
Therefore, the choice of the best material should first consider the application requirements of your inductor or transformer. From this point of view, the operating frequency and cost are important factors. The optimization of different materials is based on switching frequency and temperature rise, and the magnetic flux density .