Hysteresis

thumb|right|Electric displacement field of a ferroelectric material as the [[electric field is first decreased, then increased. The curves form a hysteresis loop.]] Hysteresis is the dependence of the state of a system on its history. For example, a magnet may have more than one possible magnetic moment in a given magnetic field, depending on how the field changed in the past. Such a system is called hysteretic. Plots of a single component of the moment often form a loop or hysteresis curve, where there are different values of one variable depending on the direction of change of another variab

the observation that, in some circumstances, warmer water can freeze faster than colder water

electronic comparator circuit with hysteresis

thumb|alt=Close-up of a drop of water (almost spherical) on blue fabric, with a shadow under it|Water bead on a fabric that has been made non-wetting by chemical treatment.

Viscoelasticity is a material property that combines both viscous and elastic characteristics. Many materials have such viscoelastic properties, especially materials that consist of large molecules. Polymers are viscoelastic because their macromolecules can make temporary entanglements with neighbouring molecules which causes elastic properties. After some time these entanglements will disappear again and the macromolecules will flow into other positions where new entanglements will be made (viscous properties).

angle between a liquid–vapor interface and a solid surface

Multiferroics are defined as materials that exhibit more than one of the primary ferroic properties in the same phase: ferromagnetism – a magnetisation that is switchable by an applied magnetic field ferroelectricity – an electric polarisation that is switchable by an applied electric field ferroelasticity – a deformation that is switchable by an applied stress While ferroelectric, ferroelastics, and ferromagnetics are formally multiferroics, these days the term is usually used to describe the magnetoelectric multiferroics that are simultaneously ferromagnetic and ferroelectric. Sometimes

relationship between soil water content and water pressure head

thumb|301x301px|Left: An example free energy given by Landau's theory with two stable states. Transforming between states requires input energy which leads to hysteresis. Right: Example stress-strain hysteresis for a ferroelastic crystal. Ferroelasticity is a phenomenon in which a material may exhibit a spontaneous strain, and is the mechanical equivalent of ferroelectricity and ferromagnetism in the field of ferroics. A ferroelastic crystal has two or more stable orientational states in the absence of mechanical stress or electric field, i.e. remanent states, and can be reproducibly switched