On the heat capacity of Ti3GeC2

被引:30
作者
Drulis, MK
Czopnik, A
Drulis, H
Spanier, JE
Ganguly, A
Barsoum, MW
机构
[1] Polish Acad Sci, W Trzebiatowski Inst Low Temp & Struct Res, PL-50950 Wroclaw, Poland
[2] Drexel Univ, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA
来源
MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY | 2005年 / 119卷 / 02期
基金
美国国家科学基金会;
关键词
thermal properties; ceramics; titanium; germanium; carbides;
D O I
10.1016/j.mseb.2005.02.045
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
In this paper, we report experimental data of the heat capacities, c, of bulk polycrystalline samples of Ti3GeC2 in the 3-260 K temperature range. The results obtained are compared with those on Ti3SiC2. The c(p) 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 gamma = 6.5 (mJ/mol K-2) and phonons with a Debye temperature OD 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 theta(D) of 513 K and an optical mode with an Einstein temperature theta(E) of 139 K. For T > 120 K, five additional optical modes with theta(E) = 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. (c) 2005 Elsevier B.V. All rights reserved.
引用
收藏
页码:159 / 163
页数:5
相关论文
共 29 条
[1]   The Raman spectrum of Ti3SiC2 [J].
Amer, M ;
Barsoum, MW ;
El-Raghy, T ;
Weiss, I ;
Leclair, S ;
Liptak, D .
JOURNAL OF APPLIED PHYSICS, 1998, 84 (10) :5817-5819
[2]   Electrical conductivity, thermopower, and hall effect of Ti3AIC2, Ti4AIN3, and Ti3SiC2 [J].
Barsoum, MW ;
Yoo, HI ;
Polushina, IK ;
Rud, VY ;
Rud, YV ;
El-Raghy, T .
PHYSICAL REVIEW B, 2000, 62 (15) :10194-10198
[3]  
Barsoum MW, 1997, J MATER SYNTH PROCES, V5, P197
[4]   Long time oxidation study of Ti3SiC2,Ti3SiC2/SiC, and Ti3SiC2/TiC composites in air [J].
Barsoum, MW ;
Ho-Duc, LH ;
Radovic, M ;
El-Raghy, T .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2003, 150 (04) :B166-B175
[5]   The MN+1AXN phases:: A new class of solids;: Thermodynamically stable nanolaminates [J].
Barsoum, MW .
PROGRESS IN SOLID STATE CHEMISTRY, 2000, 28 (1-4) :201-281
[6]   Fully reversible, dislocation-based compressive deformation of Ti3SiC2 to 1GPa [J].
Barsoum, MW ;
Zhen, T ;
Kalidindi, SR ;
Radovic, M ;
Murugaiah, A .
NATURE MATERIALS, 2003, 2 (02) :107-111
[7]   Layered machinable ceramics for high temperature applications [J].
Barsoum, MW ;
Brodkin, D ;
ElRaghy, T .
SCRIPTA MATERIALIA, 1997, 36 (05) :535-541
[8]   Room-temperature ductile carbides [J].
Barsoum, MW ;
El-Raghy, T .
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1999, 30 (02) :363-369
[9]   Thermal properties of Ti3SiC2 [J].
Barsoum, MW ;
El-Raghy, T ;
Rawn, CJ ;
Porter, WD ;
Wang, H ;
Payzant, EA ;
Hubbard, CR .
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 1999, 60 (04) :429-439
[10]   Synthesis and characterization of a remarkable ceramic: Ti3SiC2 [J].
Barsoum, MW ;
ElRaghy, T .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1996, 79 (07) :1953-1956