The interplay between magnetism and superconductivity in the heavy-fermion superconductor $\mathrm{Ce}{\mathrm{Pt}}_3\mathrm{Si}$ has been investigated using the zero-field muon-spin relaxation ($\mu \mathrm{SR}$) technique. The $\mu \mathrm{SR}$ data indicate that the whole muon ensemble senses spontaneous internal fields in the magnetic phase, demonstrating that magnetism occurs in the whole sample volume. This points to a microscopic coexistence between magnetism and heavy-fermion superconductivity.

• Received 21 September 2004

DOI:https://doi.org/10.1103/PhysRevB.71.092501