High-energy x-ray diffraction study on phase transition asymmetry of plastic crystal neopentylglycol

As a prototype material of colossal barocaloric effects, neopentylglycol is investigated by combining high-precision differential scanning calorimetric measurement and high-energy x-ray diffraction measurement. The diffraction data at constant temperatures indicate a first-order phase transition with thermal hysteresis as well as the phase transition asymmetry, specifically, the phase transition is completed faster at cooling than at heating. The analysis of resulting pair distribution function confirms the intermolecular disorder in the high-temperature phase. The phase transition asymmetry is quantitatively characterized by time-resolved x-ray diffraction, which is in agreement with the thermal measurement. Also, such an asymmetry is observed to be suppressed at high pressures.     

基于四硫富瓦烯衍生物导电LB膜研究概况

四硫富瓦烯(TTF)是具有可逆氧化还原性质的强电子给体, 由其衍生物制备的导电Langmuir-Blodgett (LB)膜可应用于分子材料及分子电子器件方面的研究. 简要综述了近年来具有代表性的基于TTF衍生物的导电LB膜及其可能用途.