Affiliations: Grupo Física de Metales, Dpto de Física, Núcleo de Sucre Cumaná, Universidad de Oriente, Venezuela | [x] Centro de Química, Instituto Venezolano de Investigaciones Científicas, IVIC, Caracas, Venezuela | [y] Departamento de Química, Instituto Universitario de Tecnología FRP, Caracas, Venezuela
Correspondence:
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Corresponding author: Diego Subero, Grupo Física de Metales, Dpto de Física, Núcleo de Sucre Cumaná, Universidad de Oriente, Venezuela. E-mail: [email protected]; [email protected]
Abstract: The additament of an impurity to a metal matrix generates a shift in the local electron density of states due to a change in the local electric potential so that an electron or electron beam will be scattered upon interaction with the ensuing potential, causing its wave function measured at a distance far removed from the source to show a quantum phase change. This phenomenon, reflected in Friedel's law, permits to relate the quantum phase shifts with both the density of states at the Fermi level and the transport properties of the system. This work calculates the electric resistivity of nanometric clusters in an aluminiumsupercell, emulating the formation of Guinier-Preston zones during pre-precipitation in an Al-Zn alloy. The density of states is evaluated each time a new atom of solute is added to the Al supercell using the ab initio method of the Density Functional Theory or DFT in its GGA and LDA approximations via the Dmol3 package of Materials Studio Software. A resistivity anomaly is obtained when, in concordance with literature reports for diluted AlZn alloys, the supercell contains 25 atoms, thus confirming that the electric resistivity anomaly during cluster formation is a consequence of both density of states variations and quantum transitions at the Fermi Level for a nanometric size in particular. The results are contrasted with those obtained via the transport equation.
Keywords: Electric resistivity, Guinier-Preston zones, nanometric cluster, DFT, Materials Studio Software
