Conductivity Of Molecular Crystals Research Articles

Thermal Conductivity of Molecular Crystals with Self-Organizing Disorder

The thermal conductivity of some orientational glasses of protonated C2H5OH and deuterated C2D5OD ethanol, cyclic substances (cyclohexanol C6H11OH, cyanocyclohexane C6H11CN, cyclohexene C6H10), and freon 112 (CFCl2)2 have been analyzed in the temperature interval 2-130 K. The investigated substances demonstrate new effects concerned with the physics of disordered systems. Universal temperature dependences of the thermal conductivity of molecular orientational glasses have been revealed. At low temperatures, the thermal conductivity exhibits a universal behavior that can be described by the soft potential model. At relatively high temperatures, the thermal conductivity has a smeared maximum and than decreases with increase in the temperature, which occurs typically in crystalline structures.

Towards nanoprobes for conduction in molecular crystals: Dibenzoterrylene in anthracene crystals

The miniaturization of electronic devices and structures brings along the quest for instruments that operate on mesoscopic and nanometric scales. In these structures, nano-instruments could elucidate the rich variety of physical processes, an understanding of which will be necessary to develop and to predict the function of new nanoscale devices. For this purpose, we propose to use single molecules as nanoprobes and to address the probes individually by means of optical single molecule microscopy and spectroscopy. This would allow us to study the conduction in molecular crystals. Here, we compare different material systems and show that dibenzoterrylene in an anthracene crystal is a promising candidate system.

Relaxational processes in molecular crystals

The influence of orientational degrees of freedom on the relaxation and kinetic processes in molecular crystals at low temperatures was studied. Libron-phonon interaction amplitudes and relaxation time constants for various processes of scattering and transformations of quasiparticles are estimated. The influence of librons on the thermal conductivity of molecular crystals was also studied.