Premium
Effect of hydrogen chemisorption on the magnetism of nickel clusters
Author(s) -
Fournier R.,
Salahub D. R.
Publication year - 1986
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560290507
Subject(s) - antibonding molecular orbital , magnetic moment , nickel , chemistry , hydrogen , atomic physics , magnetism , chemisorption , atomic orbital , spin (aerodynamics) , electron , condensed matter physics , physics , quantum mechanics , organic chemistry , adsorption , thermodynamics
Results of self‐consistent field, local spin density, scattered wave calculations are reported for nickel clusters of 10, 13, and 14 atoms and these clusters interacting with one or two chemisorbed hydrogen atoms. The pure nickel clusters all have a reasonable average atomic magnetic moment (the average over all the clusters is 0.66µ B ) and the addition of hydrogen reduces this moment in each case. The reduction of magnetic moment is clearly larger on the nickel atoms that are nearest to hydrogen but there is also a noticeable change in the moments of the other atoms of the clusters. Three factors, of varying importance for the different clusters, contribute to the changes in the overall and local magnetic moments: (i) The extra electron brought in with the hydrogen goes into a down‐spin Ni d level, reducing the moment. (ii) The reelectron duced moment is accompained by a reduced exchange splitting and consequently some up‐spin d electrons, not directly involved in the bonding to hydrogen, are transferred to lower lying down‐spin d orbitals. (iii) For atoms close to the adsorbate, d character in the local density of states is pushed above the Fermi level through antibonding interactions with the hydrogen, further reducing the moments of these atoms.