7-11 July 2014
Africa/Johannesburg timezone
Home > Timetable > Session details > Contribution details
PDF | XML | iCal

Synthesis, characterization and magnetic ordering of the semiconducting intermetallic compound FeGa3

Presented by Mr. Mustafa AHMED on 9 Jul 2014 from 17:10 to 19:00
Type: Poster Presentation
Session: Poster2
Track: Track A - Division for Physics of Condensed Matter and Materials
Board #: A.308

Abstract

Intermetallic compounds which are formed by good conductive metals are usually metallic. However, FeGa<sub>3</sub> was found to be a semiconductor with a narrow gap measured to be between 0.2 and 0.46 eV [1,2,3]. This gap mainly arises from the hybridization between the Ga 4<i>p</i> and Fe 3<i>d</i> bands [4]. The band-gap has been established experimentally by various techniques [4,5], and its origin verified by density functional theory (DFT) calculations [2,5]. FeGa<sub>3</sub> crystallizes in the tetragonal space group P4<sub>2</sub>/<i>mnm</i> (No. 136) [3]. The magnetism in this compound has not yet been observed, with various magnetization and specific heat measurements suggesting that it does not occur down to very low temperatures [4,6]. Recent work has also shown that the effect of the chemical doping on single crystal FeGa<sub>3</sub> creates a spin 1/2 local moment and drives the compound to become metallic [7]. Mössbauer spectroscopy (MES) has shown the absence of an internal magnetic field at the site of Fe confirming that no ordering above room temperature occurs [3]. FeGa<sub>3</sub> has recently been predicted to become metallic under pressure [1]. We will report on the preliminary results for this project. In particular, we will show how FeGa<sub>3</sub> single crystals has been synthesized by the self flux method, and then characterized by means of x-ray diffraction, energy dispersive analysis and MES. Furthermore, our measurements of the magnetic state of FeGa<sub>3</sub> as a function of temperature using MES will provide insights not previously reported. Our planned measurements as a function of pressure to search for a proposed metal-insulator transition will also be discussed. [1] J.M. Osorio-Guillen et al., Phys. Rev. B, 86 (2012) 235202 [2] Y. Amagai et al., J. Appl. Phys., 96 (2004) 5644 [3] Y. Imai and A. Watanabe, Intermetallics, 14 (2006) 722 [4] N. Tsujii et al., J. Phys. Soc. Jpn., 77 (2008) 024705 [5] U. Haussermann et al., J. Solid State Chem., 165 (2002) 94 [6] Y. Hadano et al., J. Phys. Soc. Jpn., 78 (2009) 013702 [7] E.M. Bittar et al., J. Phys. Conf. Ser., 200 (2010) 012014

Award

Yes

Level

MSc

Supervisor

Dr B.P. Doyle, bpdoyle@uj.ac.za, UJ

Paper

Yes

Place

Room: D Ring ground level


Primary authors

More

Co-authors

More