Hyperfine magnetic fields investigation in CeInsub(3)

Abstract

Rare earth and actinide metais, their alloys and intermetallic compounds are systems which generally present exotic properties related to a Fermi liquid behavior of highly correlated electrons. The CeIn 3intermetallic compound, with a cubic structure of the AuCu 3prototype, is one of these systems with a heavy fermion behaviour at low temperatures, exhibiting an antifemamagnetic order below 10K. In the present work a nuclear spectroscopy, the Time Differential Perturbed g-g Angular Correlation (TDPAC), was used to measure the magnetic hyperline field (MHF) at both Ce and In sites in CeIn 3 . The 1111n(111 Cd) probe nucleus was used to investigate the In site, while the 140La(140Ce) probe nucleus was used to roeasure the MHF ai the Ce site. The samples were prepared by arc melting the constituent elements in appropriate conditions. The resuits of TDPAC measurements at the In site below 10K shcrived an electric field gradient (EFG) of 4.07x1017 V/cm2 and MHF increasing up to 0.2T; and a pare magnetic interaction with MHF increasing up to 33T was observed at the Ce site. Also, in this case, the magnetization curve could be adjusted to the function (1-T/TN)b , b » 0.36, which includes Mis compound as a tridimensional "Heisenberg ferromagnet". The MHF at the Ce sites is dominated by the orbital contribution coming mostly from the 4f shell. As a nésult of APWM method calcubtion, the contributions of the 4f orbital fields for Ce in the CeIn 3and for free Ce3 ions are quite different indicating that the 4f shell of Ce exhibits a significant change inside the CeIn3 compound By other lide, at the In position, both MHF and EFG originate from the 5p shelL The small value of MHF is due to different energy as well as spatial distribution of spins in 5p sub-shells. The polarization of the 5p sub-shelis does not infiuence the EFG, as it does not occur in the region important for the EFG formation.