کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1298278 | 1498391 | 2007 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Plastic crystal behaviour in tetraethylammonium dicyanamide Plastic crystal behaviour in tetraethylammonium dicyanamide](/preview/png/1298278.png)
The plastic crystal tetraethylammonium dicyanamide ([N2,2,2,2][dca]) has been investigated with an emphasis on structure and dynamics in the plastic phase. It was found that almost all of the volume expansion occurs at the II → I transition, with no volume expansion at the melt transition (as normally observed for crystals). The conductivity of this material shows a rapid increase at temperatures below the II → I transition, reaching values ∼ 10− 3 S/cm in Phase I, and 0.1 S/cm in the melt. The NMR measurements show that there is a sudden onset of rotational motions of the cations at the plastic transition; below this temperature the cations appear static. The rotational motion of the cation in Phase I has been discussed in terms of isotropic tumbling.
Journal: Solid State Ionics - Volume 178, Issues 15–18, June 2007, Pages 1065–1071