Sains Malaysiana 40(2)(2011): 177–180

 

Magnetization and Electronic Structure of FeAs Layered Material

(Pemagnetan dan Struktur Elektronik bagi FeAs Berlapis)

 

Noriza Ahmad Zabidi*, Hasan Abu Kassim & Keshav N. Shrivastava

Department of Physics, Faculty of Science

University of Malaya, Kuala Lumpur 50603, Malaysia

 

Received: 5 January 2010 / Accepted: 21 May 2010

 

ABSTRACT

 

Magnetic induction in the superconductor (B=H +4πM) in the zero field cooled samples (ZFC) is not equal to zero. Depending upon the chemical environment it has negative value in some and positive values in some others. In the field cooled samples, the magnetization becomes paramagnetic. We have calculated the band structure of one layer of FeAs lattice with spin polarized as well as unpolarized orbitals as a function of doping by Li atoms. For n number of Li atoms (n=0, 1,…, 4), we calculated the band gap at all of the k-points as well as the Fermi energy. The reduced normal state gap was found to lead to superconductivity.

 

Keywords: Band structure; energy gap; FeAs; Fermi energy; magnetic induction

 

ABSTRAK

 

Aruhan magnet superkonduktor (B=H +4πM) di dalam sampel sejuk bermedan sifar (ZFC) tidak sama dengan sifar. Bergantung kepada persekitaran kimia, B mempunyai nilai negatif di sesetengah dan nilai positif di sesetengah yang lain. Di dalam sampel sejuk bermedan, pemagnetan menjadi paramagnet. Kami telah mengira struktur jalur satu lapisan kekisi FeAs dengan menggunakan spin terkutub dan juga spin tidak terkutub sebagai suatu fungsi pengedopan oleh atom Li. Untuk bilangan atom Li, n (n=0, 1,…, 4), kami telah menghitung jurang jalur pada semua titik-k dan juga tenaga Fermi. Jurang keadaan normal yang berkurangan didapati telah membawa kepada kesuperkonduksian.

 

Kata kunci: Aruhan magnet; jurang tenaga; FeAs; struktur jalur; tenaga Fermi

 

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*Corresponding author; email: nazca_leo@hotmail.com