Costa ribeiro effect in some cholesteryl esters

In this paper we confirm the existence of the thermodielectric effect at phase transitions of some cholesteryl esters (cholesteryl chloride, cholesteryl nonanoate and cholesteryl laurate). Significant sudden variations of the potential difference across the samples were detected at solid crystal → isotropic, isotropic → mesophase phase transitions of these liquid crystals. The variations are due to the formation of thermodielectric electrets by spontaneous polarization. The phase transitions are identified and their temperatures are in agreement with the literature.