کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9781562 | 1511632 | 2005 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
1H NMR study of the phase transitions of trissarcosine calcium chloride single crystals at low temperature
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
مواد الکترونیکی، نوری و مغناطیسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The 1H NMR line-width and spin-lattice relaxation time T1 of TSCC single crystals were studied. Variations in the temperature dependence of the spin-lattice relaxation time were observed near 65 and 130Â K, indicating drastic alterations of the spin dynamics at the phase transition temperatures. The changes in the temperature dependence of T1 near 65 and 130Â K correspond to phase transitions of the crystal. The anomalous decrease in T1 around 130Â K is due to the critical slowing down of the soft mode. The abrupt change in relaxation time at 65Â K is associated with a structural phase transition. The proton spin-lattice relaxation time of this crystal also has a minimum value in the vicinity of 185Â K, which is governed by the reorientation of the CH3 groups of the sarcosine molecules. From this result, we conclude that the two phase transitions at 65 and 130Â K can be discerned from abrupt variations in the 1H NMR relaxation behavior, and that 1H nuclei play important roles in the phase transitions of the TSCC single crystal.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Physics and Chemistry of Solids - Volume 66, Issue 10, October 2005, Pages 1739-1743
Journal: Journal of Physics and Chemistry of Solids - Volume 66, Issue 10, October 2005, Pages 1739-1743
نویسندگان
Kyuhong Lee, Moohee Lee, Kwang Sei Lee, Ae Ran Lim,