کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10640224 995880 2005 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
On the heat capacity of Ti3GeC2
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد مواد الکترونیکی، نوری و مغناطیسی
پیش نمایش صفحه اول مقاله
On the heat capacity of Ti3GeC2
چکیده انگلیسی
In this paper, we report experimental data of the heat capacities, cp, of bulk polycrystalline samples of Ti3GeC2 in the 3-260 K temperature range. The results obtained are compared with those on Ti3SiC2. The cp results are analyzed using the Debye and Einstein models and are compared to the heat capacities values calculated from first principles. At temperatures up to 10 K the main contributors to cp are electrons with γ = 6.5 (mJ/mol K2) and phonons with a Debye temperature θD of 556 K. In that temperature range only four atoms of the six in a formula unit-most likely one Ge and three Ti atoms-contribute to cp. In the 10-120 K temperature range excellent fits were obtained using a θD of 513 K and an optical mode with an Einstein temperature θE of 139 K. For T > 120 K, five additional optical modes with θE = 870 K are required to properly fit the experimental results. The ab initio calculations throughout the temperature range (4-1500 K) show reasonably good agreement with the experimental data obtained particularly at low temperatures.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: B - Volume 119, Issue 2, 25 May 2005, Pages 159-163
نویسندگان
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