Here is my "cheat sheet" on ferrite materiels.
Materiel Types
There are two basic ferrite material groups:
(1) Those having a permeability range from 20 to 850 µ are of the Nickel Zinc (NiZn) class (mix 43, 52, 61); and
(2) Those having initial permeabilities above 850 µ are usually of the Manganese Zinc (MnZn) class (Mix 31, 73, 75)
The Nickel-zinc (NiZn) ferrite cores (mix 43, 52, 61) have low permeability and exhibit high volume resistivity. Nickel-zinc ferrites have a higher resistivity and are used at frequencies from 2 MHz to several hundred megahertz.
The Manganese-zinc (MnZn) ferrite cores (Mix 31, 73, 75) have high permeabilities above 800 µ, have fairly low volume resistivity and moderate saturation flux density. They offer high 'Q' factors for the 1 KHz to 1 MHz
frequency range.
These cores are also very useful for the attenuation of unwanted RF noise signals in the frequency range of
2 MHz to 250 MHz.
MIX 31 -> 1 MHz - 300 MHz, good for HF
MIX 75/J -> 150 KHz - 10 MHz