Magnetism, Superconductivity and Quantum Criticality in the Multi-Site Cerium Heavy Fermion Compound Ce3PtIn11

The properties of the novel heavy fermion superconductor Ce$_3$PtIn$_{11}$ are investigated by thermodynamic and transport measurements at ambient and under hydrostatic pressure. At ambient pressure the compound exhibits two successive magnetic transitions at $T_1$ $\approx$ 2.2 K and $T_{\rm N}$ $\approx$ 2 K into antiferromagnetically ordered states and enters into a heavy fermion superconducting phase below $T_{\rm c}$ $\approx$ 0.32 K. The coexistence of long-range magnetic order and superconductivity is discussed in the context of the existence of the two crystallographically inequivalent Ce-sites in the unit cell of Ce$_3$PtIn$_{11}$. The experimental data allow us to construct the pressure-temperature phase diagram.