Magnetic correlations and magnetic ordering in CeCu6−xAux single crystals

✍ Scribed by H.v. Löhneysen; H.G. Schlager; A. Schröder

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 216 KB
• Volume: 186-188
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(93)90644-l

✦ Synopsis

While CeCu 6 does not show long-range magnetic order, the intersite magnetic correlations in CeCu 6 developing below 1 K are destroyed in a magnetic field of B = 2 T as evidenced by a distinct maximum in the derivative of the magnetization M, dM/dB versus B, which vanishes for T > 0.6 K. This metamagnetic-like transition thus appears to be a common feature of heavy-fermion systems without long-range magnetic order. CeCu6_xAu x alloys show long-range antiferromagnetic order for x > 0.1, e.g., T N = 0.48 K for x = 0.3 and 0.95 K for x = 0.5. The increase in the Ce-Ce distance with x stabilizes the Ce moments against formation of local Kondo singlets. The alloys have a similar easy-axis anisotropy as pure CeCum. T N is suppressed strongly for BIIc, while it hardly changes for Bllb. Likewise, the reduction of the specific heat C below T N shows the same directional dependence. Even for x = 0.5, the Kondo compensation affects the magnetization (M = 1 /~B/Ce atom in 6 T at 0.15 K) and the specific heat (C/T= 2.3 J/mol K 2 for T---, 0).