Articulo
The magnetic hyperfine field at 140Ce in nickel
Registro en:
issn:0304-3843
issn:1572-9540
Autor
Bibiloni, Aníbal Guillermo
Caracoche, María Cristina
López García, Alberto Raúl
Martínez, Jorge Alberto
Mendoza Zélis, Luis Alejandro
Mercader, Roberto Carlos
Pasquevich, Alberto Felipe
Institución
Resumen
The hyperfine interaction of140Ce in nickel has been investigated by the time-differential perturbed-angular-correlation technique (TDPAC). The probe was produced by isotope separator implantation of the fission product140Xe, the β- decay chain of which finally populates excited states of140Ce. Different spin rotation spectra were observed before and after an 8 h annealing at 415°C. The analysis of the spectra led to the conclusion that the Ce ions were in the diamagnetic 4+ state. The dominant contributions to the hyperfine interaction are two different magnetic hyperfine fields: |H; hf; 1|=385±7 kOe and |H; hf; 2|=276±12 kOe.H; hf; 1 disappears after annealing. The fraction of nuclei which observeH; hf; 2 is increased by the annealing procedure from 16% to 75%. It is assumed thatH; hf; 1 is the hyperfine field of CeNi in an unperturbed substitutional site andH; hf; 2 is attributed to Ce ions which have trapped a single vacancy. Departamento de Física