170Yb Mössbauer and neutron diffraction investigation of the antiferromagnetic phase in the Kondo lattices YbP and YbN

✍ Scribed by G. Le Bras; P. Bonville; J.A. Hodges; P. Imbert; G. Polatsek; P. Fischer; L. Keller; A. Dönni; M. Kohgi; T. Suzuki

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 865 KB
• Volume: 190
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(93)90193-a

✦ Synopsis

The Kondo lattices YbP and YbN (nonstoichiometric samples) have been investigated by 17°yb M6ssbauer spectroscopy, in the temperature range 0.085 K to 80 K in zero magnetic field in YbN and with an applied magnetic field at T = 0.045 K in YbP and YbN, and by neutron diffraction in YbN. In both compounds, the antiferromagnetic transition at TN -----0.7 K is first order and occurs through a progressive growth of paramagnetic domains as the temperature increases. The measured exchange interaction is much larger than k B TN in both compounds and it is found to be isotropic in YbP and anisotropic in YbN. The saturated magnetic moment in both compounds is reduced by 50% with respect to the value calculated from the crystal field and exchange interactions. These properties are interpreted in terms of the competition between the Kondo effect and the RKKY exchange interaction; using a model mean field NCA calculation to describe the magnetic phase, the Kondo temperatures T K are found to be near 5-10 K.