What is disaccommodation?

Disaccommodation, occurring in ferrites, is the reduction of permeability with time after a core is demagnetized. This demagnetization can be caused by heating above the Curie point, by applying an alternating current of diminishing amplitude, or by mechanically shocking the core. In this phenomenon, the permeability increases towards its original value, then starts to decrease exponentially. If no extreme conditions are expected in the application, permeability changes will be small because most of the change has occurred during the first few months after manufacture of the core. High temperature accelerates the decrease in permeability. Disaccommodation is repeatable with each successive demagnetization; thus, it is not the same as aging.