Structure, electronic, magnetic and optical properties of cubic Hf1-x(TM)xO2 (X=0, 0.25, TM = Mn, Fe, Co, Ni): A first principle investigation

In the present work the structural, electronic, optical and magnetic properties of pure cubic HfO2 and 3d transition metal (Mn, Fe, Co, Ni) doped (Hf1-xTMxO2) alloys (x = 0.25%) have been investigated by Density Functional Theory (DFT) as implemented in the FP-LAPW (full-potential augmented plane wave plus local orbital's) method employing generalized gradient approximation (GGA) and TB-mBJ exchange correlation methods. The calculated results such as lattice parameters and band gap are in good agreement with available experimental results. The calculation indicates that Hf1-xTMxO2 with x = 0 is a symmetric band gap semi-conductor but as a result of 3d TM doping, the band structure changes dramatically, presenting the half-metallic nature for all Hf1-x(TM)(x)O-2 (x = 0.25, TM = Mn, Fe, Co, Ni) with majority spin states (spin up) as metallic and minority spin states (spin down) as semi-conducting for TM = Mn, Fe, Co and for TM = Ni the majority spin states (spin up) as semi-conducting and minority spin states (spin down) as metallic. The main contributions to the magnetic moment are mainly from the doped transition metals,TM = Mn, Fe, Co and Ni atoms with partial moments of 3.67 mu B, 4.08 mu B, 2.36 mu B and 2.16 mu B, respectively. From the charge density contour plots it was found that Hf (0.)(75) TM0.25O2 compounds have merged ionic and covalent character for the Hf-O and TM-O bonds. Further we have also explored the optical properties like reflectivity, index of refraction, energy loss, optical spectrum (absorption spectrum) corresponding to the imaginary part of dielectric function in the range 0-30 eV. (C) 2019 Elsevier B.V. All rights reserved.