LOCAL-FIELD IN FERROELECTRICS - DIRECT MEASUREMENTS WITH AN OPTICAL PROBE

A local electric field, which acts on an individual molecule incorpora ted in a ferroelectric matrix, has been measured. For this purpose, ab sorption spectra of electrochromic dyes with well-defined properties o f the ground and excited states were measured ina ferroelectric copoly mer matrix above and below the phase transition temperature. The local electric field, which is due to the spontaneous polarization, has bee n evaluated from a spectral shift of the absorption maximum at the tra nsition from the paraelectric to the ferroelectric phase. (C) 1996 Ame rican Institute of Physics.