A Comparative Study of 1D Monatomic Fe-chain and 3D Fe-bulk within the Density Functional Theory (DFT)

D P Rai,A Shankar,P K Patra,R K Thapa,Sandeep Chettri

doi:10.13189/nn.2016.040301

Abstract

The structural, electronic and magnetic properties of Fe bulk and the monatomic Fe-nano wire has been theoretically investigated within the full potential linearized augmented plane wave (FP-LAPW) based on density functional theory (DFT). This work is a comparative study of Fe-bulk and the 1D Fe chain. A most commonly adopted GGA approximation is use for electron exchange correlation. In our calculation the property of bulk is predicted to be magnetic metal. Though there is no significant band gap at the Fermi level (EF) in Fe-wire, whereas the presence of deep valley (Spin up) and a peak(Spin down) at the EF shows the phenomenon of high antisymmetric density of states (DOS). The presence of high antisymmetric DOS may lead to spin polarization at the EF. Also the two anti-symmetric sharp peaks at two different energies give the exchange splitting. The exchange splitting between the degenerated d-states is dispersed and not much effective in the bulk system but the splitting between t2g states is very prominent in Fe-chain which enhanced the magnetic moment.

Highlights

The magnetic properties of nano particles, thin films and nano wires have recently attracted a lot of attention due to their potential technological applications
Among them the ferromagnetism in ferromagnetic system (Fe) monatomic wire formed on Au (111) plane was confirmed using angle-resolved photo-emission spectroscopy [7] and the same group reported that the magnetic direction of the Fe monatomic wire self organized on the terrace edge of Au (788) [8]
We examined the electronic and magnetic properties at their respective dimensions we tried to analyze the change in the magnetic moment with the change in structural dimensionality

Summary

Introduction

The magnetic properties of nano particles, thin films and nano wires have recently attracted a lot of attention due to their potential technological applications. The magnetic properties of such systems need to be treated at an atomic level, by studying their electronic structure in the framework of quantum mechanics. In principle, these properties can be determined from ab initio calculations. From the experimental works the ferromagnetism is confirmed for one-dimensional Co wire which is self assembled on the Pt (997) plane [4]. In addition Spisak and Hafner carried out ab initio calculation on the Fe monatomic wire on the Cu (11n) plane and reported that Fe becomes ferromagnetic and its Curie temperature is between 200 and 300 K [9]. We examined the electronic and magnetic properties at their respective dimensions we tried to analyze the change in the magnetic moment with the change in structural dimensionality

Model and calculation details

Result and discussion

Conclusion