Study of mechanical, electronic and optical properties of PbZrO3 and PbHfO3; DFT approach

The electronic, mechanical and optical properties of PbZrO3 and PbHfO3 have been studied by density functional theory (DFT) based modified Becke and Johnson (mBJ) potential as implemented in Wien2k code. The structural and mechanical stabilities of studied perovskites in cubic phase are confirmed by tolerance factor (0.97 for PZO and 1.0 for PHO), enthalpy of formation, specific heat capacity and positive values of elastic constants (Born mechanical stability condition). The lattice constant and bulk modulus of the studied compounds are inversely related. The band gap of PHO lies in the visible region while band gap of PZO lies in the ultraviolet region. The ductile nature has been assured by the Pugh's (B/G > 1.75) and Poisson (υ > 0.26) ratios. The optical behavior of the studied compounds has been explored in terms of dispersion, polarization, absorption, reflection, conduction and optical energy loss. The maximum absorption of light in the visible to near ultraviolet region, minimum reflection and optical loss that makes the studied materials most suitable for solar cell and optoelectronic devices.