Electrical conductivity, carrier concentration, mobility and XPS studies on thin films of metallic PdCoO₂ delafossite

C-axis textured granular thin films of PdCoO₂ were deposited at a repletion rate of 3 Hz by pulsed laser deposition technique. A narrow temperature window of 400–500 °C and a high in-situ oxygen pressure of 2 mbar are required to stabilize the rhombohedral [S.G. \(R\overline{3 }m\) $R\overline{3}m$ (166)] phase of PdCoO₂. X-ray photoemission spectrum confirms Pd is +1 oxidation state whereas the majority of Co ions are in +3 with a minor fraction in the +4 oxidation state. Raman spectrum shows peaks at 704 cm⁻¹ and 512 cm⁻¹ corresponding to A_1g and E_g modes of Pd–O allowed for this system along with an additional low intense peak at 690 cm⁻¹ arising from a weaker Pd–O which shares its oxygen with Co⁴⁺in Pd¹⁺–O–Co⁴⁺. Magneto-transport studies using six probe geometry show that the films are metallic with a resistivity of 24.09 µΩ cm and a carrier concentration of 2.66 × 10²² cm⁻³ at room temperature with a high mobility of 9.74 cm²/Vs.