A three-dimensional mapping of the Fermi surface (FS) of the heavy-fermion antiferromagnetic system ${\mathrm{CeIn}}_3$ in the paramagnetic phase was determined via measurements of the angular correlation of the electron-positron annihilation radiation for five crystal orientations. The two equivolume FS sheets observed agree with the predictions of our band-structure calculations regarding the Ce $4f$ electrons as fully localized. Moreover, a comparison of our results with the de Haas–van Alphen signals observed in the antiferromagnetic phase suggests that the f electrons retain the local atomic character in the magnetically ordered phase.

• Received 27 May 2003

DOI:https://doi.org/10.1103/PhysRevB.68.094513