|What happens to a permanent magnet's magnetic field if its temperature is lowered? What happens to a magnetic field at absolute zero?
Thermal energy is actually bad for permanent magnets, reducing or even destroying their magnetizations. That's because thermal energy is related to randomness and permanent magnetization is related to order. Not surprisingly, cooling a permanent magnet improves its ordering and makes its magnetization stronger (or at least less likely to become weaker with time). At absolute zero, a permanent magnet's magnetic field will be in great shape—assuming that the magnet itself doesn't suffer any mechanical damage during the cooling process.