Best Antenna Types for Receiving 3 Hz–30 Hz ELF Band Electrically and Magnetically

Hello everyone.
Having to experiment with receiving the 3 Hz - 30 Hz (ELF) band both electrically and magnetically, what kind of antenna do you recommend?
Thank you all.

I worked with an ELF receiver some time ago and it just used a ferrite rod antenna, like those used in medium wave radios but with many more turns of wire on the coil. You don't need to tune it, though you could if you are interested in a specific frequency,
You could use an air cored coil with many turns - try the mains winding from a small mains transformer, without the iron core (they usually have a few hundred or more turns).
Both these will be directional, which may or may not be what you want.
Either of these would provice a good basis for further experimentation.