PHYSICS · Multi-part · Fermi University Physics · Electricity, Magnetism & Electromagnetism · Magnetic materials · Magnetic materials
The Boundary-Value Problem, Ch Diamagnetism, paramagnetism and magnetic susceptibility
Problem
Someone makes three claims. Find the error in each.
((a)) "Copper is diamagnetic, so its atoms cannot also have the Larmor diamagnetic response that every electron orbit produces: a substance is one or the other."
((b)) "Pyrolytic graphite floating stably above an array of permanent magnets contradicts Earnshaw's theorem, since that theorem forbids any stable equilibrium of a magnetic body in a static field."
((c)) "The Bohr-van Leeuwen theorem is a mathematical curiosity with no physical weight, since real atoms plainly do show both diamagnetism and paramagnetism."