کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1279331 | 1497580 | 2011 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Hydrogen isotope effects on the structural phase transition of NH3BH3
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
الکتروشیمی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Hydrogen isotope effects on the structural phase transition of NH3BH3 Hydrogen isotope effects on the structural phase transition of NH3BH3](/preview/png/1279331.png)
چکیده انگلیسی
A systematic study of the structural phase transition of NH3BH3 and of its fully deuterated analogue was performed combining DSC and anelastic spectroscopy measurements. The transition is accompanied by a latent heat, and therefore is of the 1st order. On the deuterated sample the enthalpy variation is reduced of more than 20%, from 1.29 to 1.01Â kJ/mol and the transition is shifted by â¼1.5Â K toward higher temperatures. Both NH3BH3 and ND3BD3 display a temperature hysteresis between cooling and heating, thus denoting that the phase transition is of first-order. In addition, this hysteresis is extremely small (â¼0.5Â K) indicating that the coexistence region between the two phases is very narrow. During isothermal ageing, the transformation of the low-temperature orthorhombic phase into the high-temperature tetragonal one occurs with a time constant of â¼16Â min in NH3BH3 and â¼64Â min in ND3BD3, evidencing a drastic slowing down of kinetics in the deuterated compound.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Hydrogen Energy - Volume 36, Issue 13, July 2011, Pages 7927-7931
Journal: International Journal of Hydrogen Energy - Volume 36, Issue 13, July 2011, Pages 7927-7931
نویسندگان
Oriele Palumbo, Annalisa Paolone, Pasquale Rispoli, Rosario Cantelli, Tom Autrey, Abhijeet Karkamkar, Maria Assunta Navarra,