Studying Medical Errors among Hospital-Staff at Saudi Health Providers

The electronic properties of perovskite systems La(subscript 1-x)Sr(subscript x)FeO3 (x = 0, 0.67, 0.75, 1) for periodic structures and x = 0.5 for clusters) were investigated basing on density functional theory (DFT) using Dmol3 code. Our results show that LaFeO3 is antiferromagnetic insulator and SrFeO3 expresses itself as conducting material with dominated antiferomagnetic phase. The calculations also confirmed an existence of iron ions with different valences. Especially, for La0.33Sr0.67FeO3 iron ions may have valences≧+5. Investigation on polarization of clustering La0.5Sr0.5FeO3 structure reveals that this system is spontaneously strongly polarized with the polarization vector magnitude□10^2 times larger than that of the well-known ferroelectric BaTiO3.