Effects of external pressure on the narrow-gap semiconductor Ce3Cd2As6

Here we report the magnetic and electronic properties of recently discovered ${\mathrm{Ce}}₃{\mathrm{Cd}}₂{\mathrm{As}}₆$. At ambient pressure, ${\mathrm{Ce}}₃{\mathrm{Cd}}₂{\mathrm{As}}₆$ presents a semiconducting behavior with an activation gap of 74(1) meV. At 136 K, a sudden increase of the electrical resistivity and a peak in specific heat are consistent with a charge density wave transition. At low temperatures, antiferromagnetic order of the ${\mathrm{Ce}}³⁺$ ions occurs below ${T}_{\mathrm{N}}=4.0$ K with a magnetic hard axis along the $c$ axis and a ${\mathrm{\ensuremath{\Gamma}}}₆=|\ifmmode\pm\else\textpm\fi{}1/2\ensuremath{\rangle}$ doublet ground state. The application of external pressure strongly suppresses the charge density wave order, which is completely suppressed above 0.8(1) GPa, and induces a metallic ground state. No evidence for superconductivity is detected above 2 K. Conversely, the antiferromagnetic state is favored by pressure, reaching a transition temperature of 5.3 K at 3.8(1) GPa. Notably, the resistivity anomaly characterizing the antiferromagnetic order changes with increasing pressure, indicating that two different magnetic phases might be present in ${\mathrm{Ce}}₃{\mathrm{Cd}}₂{\mathrm{As}}₆$ under pressure. This change in ordering appears to be associated to the crossing of the ${T}_{\mathrm{CDW}}$ and ${T}_{\mathrm{N}}$ lines.