Electronic and magnetic structures of body-centered iron-carbon systems

The discrete variational method is used to calculate the electronic and magnetic structures of clusters representing iron-carbon systems in tetragonally distorted body centered structures. It is found that the magnetic hyperfine field is sensitive to the position of carbon. The magnitude of the field decreases when carbon resides at the neighboring and next neighboring octahedral sites and it increases on the occupation of the fifth neighboring octahedral site at the axial position. Carbon at third and fourth neighboring positions has minor effect on iron properties. The calculated properties are correlated to the interpretation of the Mössbauer results in iron martensites.