کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9781712 | 1511635 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Molecular dynamics and phase transitions in paramagnetic [Mn(H2O)6][SiF6] investigated by 2H NMR
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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 temperature dependences of 2H NMR spectra and spin-lattice relaxation time T1 have been measured for paramagnetic [Mn(H2O)6][SiF6]. The obtained 2H NMR spectra were simulated by considering the quadrupole interaction and paramagnetic shift. The variation of the spectra measured in phase III was explained by the 180° flip of water molecules. The activation energy Ea and the jumping rate at infinite temperature k0 for the 180° flip of H2O were obtained as 35 kJ molâ1 and 4Ã1014 sâ1, respectively. The spectral change in phases I and II was ascribed to the reorientation of [Mn(H2O)6]2+ around the C3 axis where the Ea and k0 values were estimated as 45 kJ molâ1 and 1Ã1013 sâ1, respectively. From the almost temperature independent and short T1 value, the correlation time for electron-spin flip-flops, Ïe, and the exchange coupling constant J were obtained as 3.0Ã10â10 s and 2.9Ã10â3 cmâ1, respectively. The II-III phase transition can be caused by the onset of the jumping motion of [Mn(H2O)6]2+ around the C3 axis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Physics and Chemistry of Solids - Volume 66, Issue 6, June 2005, Pages 1101-1106
Journal: Journal of Physics and Chemistry of Solids - Volume 66, Issue 6, June 2005, Pages 1101-1106
نویسندگان
Takahiro Iijima, Keigo Hamada, Motohiro Mizuno, Kazunaka Endo, Masahiko Suhara,