Refrigerator Magnet - Magnetic Polarization

Magnetic Polarization

Unlike most conventional magnets that have distinct north and south poles, flat refrigerator magnets made from composite materials are often constructed with alternating north and south poles on the same surface of the plane; this can be felt by taking two similar (or identical) refrigerator magnets and sliding them against each other with the "magnetic" sides facing each other: the magnets will alternately repel and attract as they are moved a few millimeters. This construction gives twice the magnetism on one side and is thus more effective at keeping the large planar magnet uniformly stuck onto the steel refrigerator than a uniformly-polarized magnet would be. It is also responsible for making the front of the magnet (the picture side) nearly non-magnetic. The arrangement is called a Halbach array.