[en] We have recorded the ⁵⁷Fe Moessbauer spectra of RE₂Fe₁₄B compounds at room temperature and at 4.2 K (RE = Y, Pr, Gd, Tb, Dy and Er). The hyperfine parameters have a strong rare-earth dependence. The hyperfine fields are strongly anisotrope. This is particularly true for the 8j₂ site. This anisotropy probably comes from the hyperfine coupling tensor

[en] Gd₂BaCuO₅ is studied with ⁵⁷Fe Moessbauer spectroscopy on a ⁵⁷Fe (1/2%) doped sample and with muon spin relaxation on an undoped sample. Cu-Cu and Gd-Gd magnetic order are found to occur simultaneously at T_N=11.8 K. The Moessbauer results suggest a first-order magnetic transition for the Cu sub-lattice

[en] We have performed an extensive numerical study of the μSR longitudinal depolarisation function, P(t), in nuclear dipole systems. The muon is assumed to be static. This work has been performed to obtain some information on two questions: 1) how much experimental information can be deduced from the P(t) shape and 2) what is the physical meaning of the observed deviation from the Kubo-Toyabe function? In addition to the numerical results we discuss the possibility of using the memory function to calculate P(t). Finally we briefly consider P(t) in the case of paramagnetic samples when the depolarisation due to the nuclear moments dominates. (orig.)

[en] The basic properties of magnetism depend strongly on the spin and orbital components of magnetization. Information about magnetic moments can be gained using new techniques, like X-ray magnetic circular dichroism or Compton scattering, developed at third-generation synchrotron sources. After a brief introduction to the basic principles of these new magnetic tools, examples of experiments of 5f-electron based systems are presented. (author)

[en] We report the first μSR measurements done on a cluster of monodisperse Pd nanoparticles. The measurements give access to the dipole field from the unpaired electron magnetic moments. We find for a two shell compound that the field is smaller than expected. The moments at the origin of the field are quasi-static, i.e. fluctuate in the microsecond time range

[en] The compound TmCrO₄ has been studied with bulk magnetization measurements, ¹⁶⁹Tm Moessbauer spectroscopy and muon spin relaxation (μSR). The Cr sublattice in TmCrO₄, which orders with a second-order magnetic phase transition at T_C=18.75 K, gradually induces magnetic order in the non-magnetic crystal field ground state of the Tm sublattice

[en] The pulsed surface muon beam of the Rutherford Appleton Laboratory is well suited to performing μSR measurements in zero and low magnetic fields with the longitudinal set-up. In this paper we describe our data analysis procedure and the effect of the collimation on the spectra. The determination of the efficiency ratio of the telescopes is discussed. We point out that for some measurements it is important to take into account the muon beam structure properly. (orig.)

[en] The knowledge of the orbital (μ_L) and spin (μ_S) magnetic moments of a magnetic material is fundamental for the understanding of its basic properties. X-ray magnetic circular dichroism (XMCD) at the uranium M-edges (3.5-3.8 keV) of a ferromagnet is a new tool which provides a direct and independent determination of μ_L and μ_S using sum rules. Here we report on recent XMCD experiments performed on uranium compounds with different degree of hybridization USb_0.5Te_0.5(localized), UFe₂ (strongly hybridized) and US (weakly hybridized). The results are compared to those obtained from the analysis of the magnetic form factor deduced from neutron scattering experiments. The importance of the value assigned to the magnetic spin dipolar operator left angle T_z right angle is emphasized. (orig.)

[en] We review the recent theoretical studies of the muon spin relaxation mechanisms in metallic ferromagnets. (orig.)

[en] Published in summary form only