%0 Journal Article
%T Evaluation of Gallium Arsenide Thermal Expansion Coefficient by Extended X-Ray Absorption Fine Structure
%A Gora Dieye
%A Sameh I. Ahmed
%A Abdou C. Wade
%A Djibril Diop
%J World Journal of Condensed Matter Physics
%P 37-46
%@ 2160-6927
%D 2019
%I Scientific Research Publishing
%R 10.4236/wjcmp.2019.92003
%X Negative thermal expansion of gallium arsenide has been investigated through temperature dependent Extended X-ray Absorption Fine Structure (EXAFS) measurements. The bond thermal expansion coefficient <span style=\"white-space:nowrap;\"><em>¦Á</em><sub><em>bond</em></sub></span> has been evaluated and compared to negative expansion<span style=\"white-space:nowrap;\"> </span>coefficient <em>¦Á</em><sub><em>tens</em></sub> due to tension effects. The overall thermal expansion coefficient is the sum&nbsp;<span style=\"white-space:normal;\">of</span>&nbsp;<em>¦Á</em><sub><em>bond&nbsp;</em></sub>and <em>¦Á</em><sub><em>tens</em></sub>. Below 60 K, <em>¦Á</em><sub><em>tens</em></sub> is greater than <em>¦Á</em><sub><em>bond</em></sub>&nbsp; yielding to a negative expansion in this temperature region. Tension effects are progressively overcome by the stretching effects in the region 60 - 300 K. The asymmetry of nearest neighbors distribution is not negligible since the gaussian approximation underestimates the bond expansion by about 0.00426 <span style=\"white-space:nowrap;\"><span style=\"white-space:nowrap;\">&amp;#197;</span></span>. This error decreases when the temperature is lowered. The accuracy in the thermal expansion evaluation and the connection between third cumulant and thermal expansion are discussed.
%K Negative Thermal Expansion
%K Tension Effects
%K EXAFS
%K Asymmetry
%K Gallium Arsenide
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=91109