My research topic

FeS (Iron Sulfide) has attracted significant attention from researchers worldwide due to its unique properties, leading to numerous experiments and computational simulations to investigate its physical characteristics. The physical properties of FeS offer several advantages for potential applications in spintronics[1], electrochemical energy storage[2], and pharmaceutical degradation[3]. FeS has two basic electronic properties, semiconducting and metallic, based on chirality, which it a highly promising candidate for alternative electrode materials for batteries[4].

FeS (Iron Sulfide) can refer a range of chemical compounds composed of Iron (Fe) and Sulfur (S). There are eight stable phases of the materials such as Troilite is a rare iron sulfide mineral with the simple formula of FeS. It is the iron-rich end member of the pyrrhotite group. Pyrrhotite has the formula Fe(1-x)S (X = 0 to 0.2) which is iron deficient. As troilite lacks the iron deficiency which gives pyrrhotite its characteristic magnetism, troilite is non-magnetic.

In the defect case, Fe vacancies are common defects in pristine FeS. It has been shown by previous researchers, who have conducted calculations using the density functional theory approach, that the presence of vacancies in the Fe atom results in lower formation energy compared to vacancies in S atoms. This indicates that Fe vacancies are more likely to occur in pristine FeS compared to S vacancies[1].

Crystal defects, such as point defects, are commonly found in crystalline materials. These defects arise due to several reasons, including crystal growth conditions, impurities, and radiation exposure. Point defects can occur during crystal growth if the atoms or molecules are not arranged in the correct crystal lattice pattern due to a change in temperature or pressure. Impurities, such as foreign atoms, can also create point defects if they do not fit properly into the crystal lattice. Radiation exposure can damage the crystal structure and create point defects, resulting in changes in the material’s electronic, optical, or magnetic properties. Understanding the formation and effect of point defects in crystals is essential for designing and developing new materials for technological applications.

Structural defects on the bulk of FeS have an interesting effect on its physical properties. During the growth process of FeS, defects such as point defects may arise. Previous studies have reported that monovacancy in pristine FeS can change its electronic properties depending on the concentration of defect. Furthermore, the presence of FeS defects in semiconducting FeS can lead to a reduction in its energy gap. However, the impact of defects on the optical properties of FeS is not yet extensively explored.

The topic of discussion is the impact of structural defects on the surface of FeS, which can change its electronic and optical properties. The approach being used to understand this impact is first principle calculations using Quantum Espresso software.

Ref:

[1] Irham,M.A.,Muttaqies,F.,Bisri,S.Z.,&Iskandar,F(2021).Role of Intristic Point Defects on the Electronic Structure of Metal-Insulator Transitioon h-FeS. The Journal of Physical Chemistry Letters.ACS

[2] Xu, Q.T.,Li,J.C.,Xue,H.G.,&Gu,S.P.(2018).Binary Iron Sulfide as Anode Materials for Rechargeable Battereis: Crystal Structures, Syntheses, and Electrochemical Performance. Journal of Power Sources.Elsevier

[3] Kim, E.-J.,Kim,J-H.,Azad,A.-M.,&Chang, Y-S.(2011).Facilie Synthesis and Characterization of Fe/feS Nanoparticles for Environmental Applications.Applied Materials&Interfaces.ACS

[4] Yuvaraj,S.,Veerasubramani,G.K.,Park,M.S.,Thangvei,P.,Kim,D.W.(2020).Facile Synthesis of FeS2/MoS2 Composite Interwined on rGO Nanosheets as a High-Performane Anode Material for Sodium-Ion Battery.Jpurnal of Alloys and Compounds