barium vs. strontium ferrite

[RyreInc]

I'm trying to find the differences (if any) between these two ferrites, but am not having much luck. Does anyone have some pointers as to where to look?

From what I can find, the two materials are very similar and generally interchangeable, with Sr having potentially slightly higher BHmax and Hc than Ba. The same source (from 1979) also says, "Manufacturers rarely state whether Ba, Sr, or a mixture of the two is used."

Thanks!