Chalcopyrite Al(Ga, Mn)As2 and AlGa(As, P) Quaternary Semiconductor: A First-principle Study

Authors Byung-Sub Kang , Kie-Moon Song

Nanotechnology Research Center, Nano Science & Nechanical Engineering, Konkuk University, Chungju, 27478, South Korea

Issue Volume 11, Year 2019, Number 2
Dates Received 18 December 2018; revised manuscript received 04 April 2019; published online15 April 2019
Citation Byung-Sub Kang, Kie-Moon Song, J. Nano- Electron. Phys. 11 No 2, 02006 (2019)
PACS Number(s) 71.15.Ap, 71.55.Gs
Keywords Half-metallic, Ferromagnetism (7) , Chalcopyrite (3) , Spin-electronics, First-principles (2) .

The electronic and magnetic properties for a diluted magnetic semiconductor of 3d-metal Mn-doped AlGaAs2 and AlGa(AsxP1 – x)2 chalcopyrite alloys are investigated by using the first-principle calculations. The chalcopyrite AlGaAs2 and AlGa(As, P) quaternary compounds have semiconductor characters with a small band-gap. For the system of Al(Ga, Mn)As2 chalcopyrite, the ferromagnetism with high magnetic moment of Mn is originated from the exchange couplings between Mn 3d- and As 4s-, or As 3d-bands. The Mn moments couple to holes by an on-site exchange interaction due to the overlap of the hole wave-function with the d-orbitals of the local Mn electrons. The itinerant holes of Al and Ga sites couple ferromagnetically to the local Mn-moments via the exchange interaction. While the itinerant holes in As 3d-, or As 4s-bands are aligned antiferromagnetically to the local Mn moments via the exchange interactions. When the concentration of dopants is high with over a dilute concentration, a long-range ferromagnetic state among the local moments is established by the itinerant holes. This mechanism is usually denoted as hole-carrier mediated ferromagnetism. A long-range ferromagnetism among the Mn local moments is established by the high enough hole densities of partially unoccupied majority of As 3d- and majority of As 4s-bands, by the exchange interaction between dopant Mn and the localized carriers trapped in the interstitial sites. The Al(Ga, Mn)As2 exhibits the ferromagnetic and half-metallic states. For the increasing Mn concentration (up to 6.25 % in our work), it is maintained the ferromagnetic and half-metallic characters.

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