Pressure effect on magnetic properties of valence fluctuating system Ce(Ni₁₋xCux)₅

Abstract

Magnetic susceptibility χ of the isostructural Ce(Ni₁₋xCux)₅ alloys (0 ≤ x ≤ 0.9) was studied as a function of the hydrostatic pressure up to 2 kbar at fixed temperatures 77.3 and 300 K. A pronounced pressure effect on susceptibility is found to be negative in sign and nonmonotonously dependent on the Cu content, showing a sharp maximum at x 0.4. The experimental results are discussed in terms of the valence instability of Ce ion in the studied alloys. For the reference CeNi5 compound the main contributions to χ and their volume dependence are calculated ab initio within the local spin density approximation, and appeared to be in close agreement with experimental data.