Arrott plot

In condensed matter physics, an Arrott plot is a plot of the square of the magnetization ${\displaystyle M^{2}}$ of a substance, against the ratio of the applied magnetic field to magnetization ${\displaystyle H/M}$ at one (or several) fixed temperature(s). Arrott plots are an easy way of determining the presence of ferromagnetic order in a material. They are named after American physicist Anthony Arrott who introduced them as a technique for studying magnetism in 1957.