The System Pentacene in p-Terphenyl

As the case of a mixed crystal, we consider p-terphenyl doped with pentacene. In the low-temperaturep-terphenyl lattice, pentacene exhibits four distinct sites denoted by Oi, O2, O3, O4. These sites result from the p-terphenyl phase transition at 190 K, in which p-terphenyl ring rocking freezes out [246]. The final ring distribution produces a low-temperature unit cell that contains conformationally different p-terphenyl 

The p-terphenyl pentacene crystals used in the experiment described below were grown from the melt by the Bridgman technique using extensively zone-refined p-terphenyl. The pentacene obtained from Aldrich was vacuum sublimed once before 

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