Optical properties of PMACB and PMABB crystals

Thermal Expansion of (CH3NH3)5Bi2X11(X=Cl, Br) Crystals in the Temperature Range from 80 to 300 K

“…The pyroelectric measurements [10] recorded a diffused anomaly below 180 K interpreted as a structural PT between two polar phases. Numerous techniques: Raman [6], birefringence [11] and conduction calorimetry [12] have detected a diffused physical anomaly in the vicinity of 170 K. On the other hand, the polarizing-microscope observations of MAPCB around 170 K by Iwata and Ishibashi [13] did not confirm the existence of the PT. The dilatometric studies were performed on MAPCB [14] and MAPBB [15] only in the vicinity of the ferro-paraelectric PT (I => II).…”