Physical properties investigation of tetragonal BaT₂P₂(T= Ru, Pd)

The structural, thermal, electrical transport, and magnetic properties of ternary compounds BaT2P2(T=Ru, Pd) are reported together with electronic structure calculations. Our results show that BaRu2P2crystallises in the layered tetragonal ThCr2Si2-type structure (space groupI4/mmm) whereas BaPd2P2adopts the primitive tetragonal CeMg2Si2-type structure (space groupP4/mmm). The combined experimental results and electronic structure calculations suggest metallic and diamagnetic ground states for both materials. Electrical transport measurements further indicate non-Fermi liquid behaviour at low temperatures. Notably, BaRu2P2exhibits an anomalous feature in the magnetic susceptibility atT∼260K, similar to that observed in BaRu2As2. A comparison between the bare density of states obtained from electronic structure calculations and the experimentally estimated values suggests the presence of strong correlation effects in the material. Furthermore, the heat capacity of BaPd2P2, calculated using the full phonon dispersion relation, is in good agreement with the experimental data, particularly at low temperatures, highlighting the significant contribution of optical phonon branches toCpin this temperature range.