Density Functional Tight-Binding Calculations to Predict Hubbard Interaction Parameters in Full-Heusler Alloy System Fe2MnAl

1.Abstract

Heusler alloys, first discovered by F. Heulser in 1903, still attract many researchers due to their fascinating phenomena such as high Tc temperature, Half-metalicity, transport properties, magnetic properties, and etc. One of the most fascinating properties of this material is their magnet moment values that can be predicted using simple calculation called Slater-Pauling rule. To unravel such as this phenomenon, First Priciple Study such as Density Functional Theory (DFT) had been conducted by many researchers to predict the magnetic moment of this material. Although DFT calculations can predict the magnetic moment of many Heusler Alloys, DFT is still not be able to give the information about the value of Hubbard parameters that refer to their specific magnetic moment value of the Heulser Alloy. On the other hand, the interactions that strongly occur in the Heusler Alloy system, particulary for magnetic moment formation, are estimated emerging from such as Hubbard interaction, and spin interaction. Therefore, we propose to do a theoretical study of Full-Heusler Alloy system Fe2MnAl to obtain the Hubbard parameter values (U) by using DFT-based tight-binding (TB) calculation by incorporating the Hubbard repuslion (U) and spin interactios (J), and solve it using Mean Field Theory (MFT) framework. We extract the TB parameteres by using DFT+Wannier90 to obtain the more realistic tight-binding paramaters. Our main goals are to obtain the preddicted Hubbard Parameter value refers to the specific of U and J value.
 

2.Keywords
Heusler Alloy, Fe2MnAl, Magnetic Moment, Tight-Binding, Density Functional Theory, Mean-Field Theory
3.Objective

1. to obtain the Hubbard parameter that refers to the magnetic moment prediction value of Fe2MnAl using DFT-based tight-binding calculations.
2. to provide informations about Heulser Alloy for researchers who would study further in the future.

4.Methodology

This theoretical study of Full-Heusler Fe2MnAl is modeled using DFT-based Tight-Binding model. We construct the Hamiltonian model and incorporate the Hubbard (U), spin interaction term (J), and solve it using Mean Field Theory framework.

5.Team

Anugrah Azhar, M.Si. (Universitas Islam Negeri Syarif Hidayatullah Jakarta)
Muhammad Aziz Majidi, Ph.D. (Universitas Indonesia)

6.Computation plan (required processor core hours, data storage, software, etc)

To execute our calculations, we need several computational programs as follow:
1) HCP 2.0 (suggested from WhatsApp LIPI GRID group member)
2) Fortran90 (Main program)
3) Openmpi (parallel computing)
4) Lapack (to handle huge matrices operation)
5) Blas (environment for Lapack)
6) Quantum-Espresso (DFT program)
7) Wannier90 (to extract tight-binding parameter)
8) YAMBO (for DFT+GW+BSE calculation)
9) m4 (environment for YAMBO)
10) netcdf4 (environment for YAMBO)
11) 16 computing nodes (128 cores)

7.Source of funding
-
8.Target/outputs
The research result would be published in indexed National/International reputational Journal
9.Date of usage
24/12/2018 - 31/12/2019
10.Gpu usage
-
11.Supporting files
12.Created at
19/12/2018
13.Approval status
approved