ES22-Afrassa

Author: Afrassa, Mesfin Asfaw  - Adama Science and Technology University 

Title: First principle study on the effect of Mn substitution in NaFeAs

Abstract: This work present the study on the effect of Mn substitution in NaFeAs applying density functional theory(DFT) as implemented in quantum ESPRESSO. In order to investigate this effect, 50% Mn-substitution on Fe site of NaFeAs were done. The band structure and the density of states(DOS) are calculated for non-magnetic (NM) and collinear-magnetic orderings. Comparison was done between NaFeAs and NaFe0.5Mn0.5 As. The calculated band structures indicates that there is a significant change due to Mn in AFM ordering, where the two bands are completely different at the first Γ-point and in between the second Γ-point and the first Z-point. The DOS result shows that the Fe states dominated in the vicinity of the EF , with only a small contribution from the As and Na. Using the DOS value and some approximation for BCS type, the Tc were calculated for NaFeAs and we obtained T c = 9.33k. The DOS in the presence of Mn decreases for AFM ordering and it seems that the effect of Mn on 1111-family is not similar with 111-family of IBSC. The calculated magnetic moment indicated that the material has a Ferii magnetic behavior.

Other authors: Mark Pederson, The University of Texas at El Paso