Preisach modeling of ferroelectric pinched loops

The Preisach approach is applied to model ferroelectric pinched (or constri cted) loops. Starting from the existence of distributed switchable dipolar defects in the material and a corresponding distribution function, an analy tical expression for the resulting ferroelectric loop is obtained. The corr esponding hysteresis shape is indeed showing a clear pinching. Consideratio ns about defect distribution expression and ways to characterize it from th e loop are also made. It is finally suggested that such a description can b e applied to any system exhibiting a pinched loop. (C) 2000 American Instit ute of Physics. [S0003-6951(00)02651-6].