Main Question or Discussion Point
Is there a material that blocks or reflects magnetic fields such as a field from a neodymium magnet?
Are you saying you've been able to knock an MRI down to nT with mu metal? May I ask how?In the construction of passively shielded MRI suites we call it a shielding material. On one side of the shielding you may have a field of several tesla and on the other side a field of several nanotesla. So to me it seems fair to call that "blocking" the field.
Obviously reflecting is the wrong word, since that refers to a wave behavior. But to me "blocking" seems close enough to "shielding".