PHASE FRONT SHAPES AND THERMAL DISTRIBUTIONS FOR KD2PO4 SAMPLES IN A ROTATING THERMAL-GRADIENT

The shape of the DKDP phase front is observed along three perpendicula r directions during the coexistence of the paraelectric and ferroelect ric phases for different orientations of an external thermal gradient G(e). Quasi-planar and zigzag shapes are then described. The thermal d istribution inside the sample can be well represented by a thermal gra dient G(i) in the middle of a non-plate-shaped sample. The important e ffect of the sample's corners is also demonstrated.