| Autor: |
Jan Kommandeur, C Haas, S Vansmaalen, Jl Deboer |
| Rok vydání: |
1985 |
| Předmět: |
|
| Zdroj: |
Physical Review. B: Condensed Matter and Materials Physics, 31(6), 3496-3503. AMER PHYSICAL SOC |
| ISSN: |
0163-1829 |
| Popis: |
The mean thermal-expansion tensor is determined for a number of N-substituted-morpholinium tetracyanoquinodimethanide salts by measuring the lattice parameters at various temperatures. A large anisotropy is found. The expansion coefficient has its highest value approximately along the stack axis of the tetracyanoquinodimethane (TCNQ) molecules. To explain this anisotropy, a simple model is given in which the separate contributions of the librational phonon modes and the translational phonon modes to the thermal expansion are calculated. An argument based on the number of degrees of freedom leads immediately to an expansion along the stack three times larger than the expansion in directions perpendicular to the stack. This simple estimate is confirmed by a more precise analysis |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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