Hysteresis is a lag in response to stress or electromagnetic force, dependent on previous forces applied. Ferromagnetic hysteresis is used for magnetic data storage, while memristors mimic synapses in the brain. Elastic materials can exhibit thermal hysteresis, causing energy loss. The hysteresis model has applications in various disciplines.
Hysteresis is a quality most often seen in magnetic and elastic materials where a response to stress or electromagnetic force on the material lags behind the actual application of force. The reaction also depends on the previous forces applied to the material and not only on the current stress conditions to which it is subjected. In simpler words, it is the history dependence of a system and the root term of the word actually means to be late or fall behind.
In ferromagnetic hysteresis, the principle is invoked for recording information on magnetic tapes, credit card strips, and more. Because a magnetic hysteresis field is applied to the recording medium and released, the medium does not return to a state of zero magnetization. Instead, a new level of order is added to the magnetic particles in the material, representing the structure of the data recorded there. This sort of residual magnetic memory can only be erased by applying a magnetic charge in the opposite direction, known as the hysteresis loop. The implanted magnetic charge can otherwise be nearly permanent, a useful feature when storing information, and has been used extensively for audio cassettes and computer hard drives.
The hysteresis loop property can also be used to erase magnetic data by applying a reverse magnetic field to the medium. One in the same direction can also be employed to override the previous pattern. This repeatable characteristic or hysteresis loop in ferromagnetics, however, is not present in the properties of other materials.
Memristors, or memory resistors, are components that demonstrate the principle of a hysteresis circuit. They have the ability to maintain a memory of the hysteresis current flowing through them by changing their relative resistance in response to it. These devices mimic the way synapses work in the human brain, which has caught the attention of military researchers at the Defense Advanced Research Projects Agency (DARPA) in the United States. Research in 2010 aimed to develop supercomputer power that would be small enough to be packed into a two-liter volume and have the equivalent of a cat’s brain in terms of intelligence.
Materials that are somewhat elastic, such as thin metals, can exhibit a thermal hysteresis effect. Changes in the alignment of metal atoms when bending the tines of a fork back and forth will demonstrate hysteresis, but, unlike magnetic materials, metal becomes less reactive with repeated applications of force. This is referred to as work hardening and eventually causes the metal to become brittle and crack. The metal lags in response to the force and eventually breaks, causing energy to be lost as heat, which is referred to as hysteresis loss.
The hysteresis model has applications in a wide range of scientific, engineering and even economic disciplines. Russian mathematicians started modeling nonlinear systems based on the principle in the 1970s. They later developed theories such as the Preisach model, which could be used to describe the phenomenon of hysteresis in a wide range of sciences, from economics to tectonics and superconductivity.
Protect your devices with Threat Protection by NordVPN
