ARkival measures the coercivity of magnetic material from a magnetic hysteresis loop measured with a vibrating-sample magnetometer (VSM). Coercivity is measured and reported in Oersted or ampere/meter units and denoted by Hc in the Hysteresis loop. In the VSM measurement, the coercivity Hc is measured by applying a (reverse) magnetic field to reduce the sample magnetization to zero after the samples has been magnetized to saturation. Coercivity is defined from a Hysteresis loop at the point where H Field has a value at “0”. Ferromagnetic materials with high coercivity are called magnetically hard, and materials with low coercivity are said to be magnetically soft.
The Coercivity, also called coercive field or coercive force, is defined in a ferromagnetic material as the value of the applied external magnetic field to reduce the magnetization of a material (or sample) to zero after the sample has been magnetized to saturation. The magnetic parameter of Coercivity is a measure the resistance of a ferromagnetic material to becoming demagnetized.