First-Principle Investigation of La0.7Ba0.3Mn(1-x)FexO3 Structural Properties Using CASTEP

We conducted first-principles Density Functional Theory (DFT) calculations using the CASTEP software package to investigate the crystal structure and mechanical properties of Fe³⁺-doped La_0.7Ba_0.3MnO₃ material at the Mn³⁺ site, with doping concentrations ranging up to 50%. Through geometry optimization, we simulated the X-ray diffraction (XRD) pattern. We observed that the doping of Fe did not result in a shift in the peak positions of the diffraction pattern. However, it led to an increase in intensity at the [012] peak and the splitting of peaks [104] and [110]. Regarding the mechanical properties, we examined the elastic constants and observed a reduction in the Bulk, Shear, and Young's modulus values. The Shear and Bulk modulus and Poisson's ratio indicated that La_0.7Ba_0.3Mn_(1-x)Fe_xO₃ becomes less ductile with increased Fe³⁺ doping content. Furthermore, we performed calculations for the Debye temperature, which revealed a decrease in the thermal conductivity of the La_0.7Ba_0.3Mn_(1-x)Fe_xO₃ material.