G. P. Kopitsa, S. V. Grigor'ev, V. V. Runov, S. V. Maleyev, V. M. Garamus, A. G. Yashenkin, “Study of the heavy-fermion compound CeRu2Si2 by the small-angle neutron scattering method”, Pis'ma v Zh. Èksper. Teoret. Fiz., 2005, Volume 81, Issue 11,Pages 688

This article is cited in 4 papers

FIELDS, PARTICLES, AND NUCLEI

Study of the heavy-fermion compound CeRu₂Si₂ by the small-angle neutron scattering method

G. P. Kopitsa^a, S. V. Grigor'ev^a, V. V. Runov^a, S. V. Maleyev^a, V. M. Garamus^b, A. G. Yashenkin^a

^a B. P. Konstantinov Petersburg Nuclear Physics Institute, Russian Academy of Sciences
^b GKSS Research Centre D-21502 Geesthacht, Germany

Abstract: In order to directly observe neutron scattering by heavy fermion quasiparticles at low temperatures, a CeRu₂Si₂ single crystal has been studied by the small-angle neutron scattering method. In the experiment, neutron scattering is observed at T = 0.85 K for momentum transfers q ≤ 0.04 Å⁻¹, which is treated as the orbital component of magnetic scattering by heavy fermion quasiparticles. It has been found that the application of a magnetic field H = 1 T leads to both an increase in the observed scattering and its anisotropy with respect to the field direction. Moreover, measurements in the magnetic field reveal additional scattering for q > 0.04 Å⁻¹, which is well described by a Lorentzian and is interpreted as neutron magnetic scattering by spin-density fluctuations with a correlation radius R _c ≈ 30 Å.

PACS: 61.12.Ex, 71.27.+a

Received: 11.05.2005