Effect of pressure on the magnetic susceptibility of CeCo2

The magnetic susceptibility, chi, of CeCo2 compound has been measured under pressure up to 2 kbar at T = 78 and 300 K, and a pronounced pressure effect, d Inchi/dP similar or equal to -5 Mbar(-1), is revealed. In order to analyze the experimental magnetovolume effect, d In chi/d In V, the volume-dependent electronic structure of CeCo2 has been calculated ab initio by employing a relativistic full-potential LMTO method. The calculations have brought out strong hybridization of the itinerant 4f (Ce) and 3d (Co) states, which leads to a filling of the peculiar bonding band. It is demonstrated that the magnetic properties of CeCo2 are consistent with itinerant behavior of the 4f electrons of cerium. The large volume derivative of the effective electron-electron interaction parameter, d In I/d In V similar or equal to - 1.7, implies a predominant role of the short-range correlations, in accordance with the Hubbard model. (C) 2002 Elsevier Science B.V. All rights reserved.