| Autor: |
Alexander Zhuravkov, Lyudmila Matzui, A. Samchuk, Ludmila Vovchenko |
| Rok vydání: |
2006 |
| Předmět: |
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| Zdroj: |
Journal of Physics and Chemistry of Solids. 67:1168-1172 |
| ISSN: |
0022-3697 |
| DOI: |
10.1016/j.jpcs.2006.01.042 |
| Popis: |
Electric resistivity of compacted composite materials (CM) based on thermoexfoliated graphite TEG and TEG–Fe 3 O 4 +Fe under compression (along a -axis or C -axis) has been investigated by four-probe method. The estimation of the effective Yung module along a -axis E eff( a ) for compacted TEG gives the values ∼1.6 GP a that is higher than E eff( C ) along C -axis—1.0 GPa. The fixing of iron particles on TEG surface leads to increase of E eff( a ) up to 2.4 GPa. It was shown that several different processes could occur under compression of specimens: additional compacting of specimen under loading due to plastic deformation (the improvement of contact between particles, R decreases); specimen micro-rupture ( R increases); the rotation of graphite macro-planes ( R a increases due to anisotropy of TEG particles' resistivity ρ ); the increasing of contact areas between TEG particles and contact pressure at compressing (the decrease of R , that is reversible in a case of elastic deformation of specimens). The irreversible changes in the value of normalized resistance R / R 0 were shown to be in direct proportion to the plastic deformation e plast at compression along a -axis while R / R 0 ( σ ) has maximum at compression along C -axis. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect