Density-Functional Theory of Vibrations in Ni1−xVx Clusters

• Published in: Journal of cluster science 2011-09, Vol.22 (3), p.491-499
• Main Authors: Rosli, Ahmad Nazrul, Zabidi, Noriza Ahmad, Kassim, Hasan A., Shrivastava, Keshav N.
• Format: Article
• Language: English
• Subjects: Approximation; Catalysis; Chemistry; Chemistry and Materials Science; Clusters; Density functional theory; Electrons; Energy; Fermi surfaces; Ferromagnetism; First principles; Inorganic Chemistry; Mathematical analysis; Nanochemistry; Nickel; Original Paper; Oscillations; Phase transitions; Physical Chemistry; Quantum mechanics; Vanadium; Vibration
• ISSN: 1040-7278; 1572-8862
• DOI: 10.1007/s10876-011-0388-0

We have performed the calculation of the vibrational frequencies, Fermi energy and binding energy for several clusters of Ni and vanadium atoms by using the first principles. The calculations are performed by using the density-functional theory in the local-density approximation with spin polarized orbitals. The calculation of vibrational frequencies shows that some of the clusters have positive vibrational frequencies which describe the oscillations of the stable clusters. The negative vibrational frequencies indicate that these clusters are instable with respect to these vibrations when no energy of this frequency is supplied. We find that for vanadium concentration less than 11.1% the clusters of Ni and V atoms are not stable. Hence ferromagnetism in Ni is predicted below 11.1% vanadium. We find the vibrational frequencies of several clusters for which the vanadium concentration is more than 11.1%. We are able to find a phase transition by use of quantum mechanics alone without the use of classical mechanical variables or thermodynamic variables such as temperature.