New atom movement mechanism for tracking path on disordering AuCuI (A8AuA4Cu ) compound
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Powder Metallurgy Research Institute, Central South University, Changsha 410083, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
4. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
5. College of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China;
6. School of Physics and Electronics, Central South University, Changsha 410083, China)
2. Powder Metallurgy Research Institute, Central South University, Changsha 410083, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
4. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
5. College of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China;
6. School of Physics and Electronics, Central South University, Changsha 410083, China)
Abstract: Taking experimental path on disordering AuCuI(A8AuA4Cu) composed of A8Au and A4Cu stem alloy genes as an example, three discoveries and a method were presented. The ability of AuCuI(A8AuA4Cu) to keep structure stabilization against changing temperature is attributed to the fact that the A8Au and A4Cu potential well depths greatly surpass their vibration energies, which leads to the subequilibrium of experimental path. A new atom movement mechanism of AuCuI(A8AuA4Cu) to change structure for suiting variation in temperature is the resonance activating-synchro alternating of alloy genes, which leads to heterogeneous and successive subequilibrium transitions. There exists jumping order degree, which leads to the existence of jumping Tj-temperature and an unexpected so-called “retro-effect” about jumping temperature retrograde shift to lower temperatures upon the increasing heating rate. A set of subequilibrium holographic network path charts were obtained by the experimental mixed enthalpy path method.
Key words: intermetallics; alloy gene; order/disorder transformation; resonance activating-synchro alternating mechanism; thermodynamic properties; equilibrium and subequilibrium holographic network path charts