140Ce probe nuclei used to measure magnetic hyperfine field in rare-earth magnetic compounds

by Artur Carbonari (IPEN)

Wednesday 15 Jan 2014, 14:30 → 15:30 Europe/Zurich

26-1-022 (CERN)

Measurements of the magnetic hyperfine field (B_hf) at nuclear sites in magnetically ordered rare-earth (R) compounds can be used to fully characterize a magnetic system. ¹⁴⁰Ce, for instance, is a probe nucleus suited to investigate the local magnetism in rare-earth compounds once it substitutes rare-earth ions. However, as Ce⁺³ ions have one 4f electron, a contribution from the probe itself to the magnetic hyperfine field arises, which could mask contributions from the neighboring host ions. In the present talk we will show how it is possible to separate, from experimental measurements using Perturbed gamma-gamma angular correlation (PAC) spectroscopy, the contributions from the host and the Ce probe to the B_hf in two series of compounds: RAg and RRh₂Si₂. Moreover, we will also show how PAC can provide useful information on another very interesting and yet not well understood problem: the anomalous temperature dependence of B_hf at probe nuclei of magnetic rare-earth ions diluted in magnetic intermetallic compounds.
 

Slides Presentation_CERN_Artur_W_Carbonari.pdf Presentation_CERN_Artur_W_Carbonari.pptx