These alloys are used for applications that require magnets in the form of strips, rods and wires or for those necessary for the production of stamped, bent and machined parts. Semi-hard materials include MAGNETOFLEX, SENSORVAC and SEMIVAC. MAGNETOFLEX refers to a permanent magnetic alloy composed of cobalt, iron and vanadium. Typical applications for this form of alloy are motors, compass needles and tachometers. SENSORVAC and SEMIVAC are cobalt-free alloys composed of iron and nickel. They are manufactured in tape and wire form and used in electronic article surveillance (EAS) systems. 1.6 Magnetic anisotropy Magnetic anisotropy is defined as the directional dependence of the magnetic properties of materials. Strong easy axis anisotropy is a prerequisite for hard magnetism, while near zero anisotropy is desirable for soft magnets. Generally, the tendency of magnetization to lie along an easy axis is represented by the energy density