A comparative study of structural, electronic and magnetic properties of DyOCl and HoOCl lanthanide oxychlorides: first-principles predictions of DFT, DFT plus U and DFT plus U plus SOC methods

Apart from their fundamental interest, lanthanide compounds have potential implications as luminescent, catalytic, magnetic as well as biomedical materials for diverse applications. In this paper we report first time the electronic and magnetic properties of two members of lanthanide oxychloride family, namely- DyOCl and HoOCl from the first-principles calculations based on density functional theory (DFT). For the self-consistent DFT calculations, we incorporated the full-potential linearized augmented plane-wave (FP-LAPW) method using various DFT methods and DFT + U method without and with spin-orbit coupling (SOC). For the electronic structure calculations, the exchange-correlation energy functionals in Kohn-Sham equation are treated within local-spin-density-approximation (LSDA) and Generalized-Gradient-Approximation (GGA) in conjunction with Perdew-Bruke-Ernzerhof (PBE) and Wu-Cohen (WC) parameterization. In particular, a comparative analysis of electronic and magnetic properties is presented with LSDA, PBE-GGA, WC-GGA and GGA + U methods without and with SOC coupling. Both compounds are predicted to be half-metallic (HM) ferromagnetic (FM) within LSDA approximation, whereas within GGA + U approximation DoOCl is semiconducting while HoOCl is HMFM. On the other hand, the GGA + U scheme under FM and antiferromagnetic (AFM) ordering predicts that both DyOCl and HoOCl are metallic in AFM ordering while they show insulating nature in FM ordering.