Editing Magnet (section)

=== Flexible magnet ===<!-- This subsection is referenced from elsewhere. -->

Flexible magnets are composed of a high-[[coercivity]] [[ferromagnetic]] compound (usually [[ferric oxide]]) mixed with a resinous polymer binder.<ref name=":0" /> This is extruded as a sheet and passed over a line of powerful cylindrical permanent magnets. These magnets are arranged in a stack with alternating magnetic poles facing up (N, S, N, S...) on a rotating shaft. This impresses the plastic sheet with the magnetic poles in an alternating line format. No electromagnetism is used to generate the magnets. The pole-to-pole distance is on the order of 5&nbsp;mm, but varies with manufacturer. These magnets are lower in magnetic strength but can be very flexible, depending on the binder used.<ref>{{cite web|title=Press release: Fridge magnet transformed|url=http://www.riken.jp/en/research/rikenresearch/highlights/6543/|publisher=Riken|language=en|date=March 11, 2011|url-status=live|archive-url=https://web.archive.org/web/20170807234355/http://www.riken.jp/en/research/rikenresearch/highlights/6543/|archive-date=August 7, 2017}}</ref>

For magnetic compounds (e.g. [[Neodymium|Nd]]<sub>2</sub>[[Iron|Fe]]<sub>14</sub>[[Boron|B]]) that are vulnerable to a [[grain boundary]] corrosion problem it gives additional protection.<ref name=":0" />