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Study of the Dilute Magnetic Semiconductor, Ga1-x MnxP and undoped GaP, with Hard X-Ray Photoemission and Angle-Resolved Photoemission.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Study of the Dilute Magnetic Semiconductor, Ga1-x MnxP and undoped GaP, with Hard X-Ray Photoemission and Angle-Resolved Photoemission./
作者:	Keqi, Armela.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2018,
面頁冊數:	156 p.
附註:	Source: Dissertations Abstracts International, Volume: 80-09, Section: B.
Contained By:	Dissertations Abstracts International80-09B.
標題:	Condensed matter physics. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10982743
ISBN:	9780438930964

Study of the Dilute Magnetic Semiconductor, Ga1-x MnxP and undoped GaP, with Hard X-Ray Photoemission and Angle-Resolved Photoemission.
Keqi, Armela.

Study of the Dilute Magnetic Semiconductor, Ga1-x MnxP and undoped GaP, with Hard X-Ray Photoemission and Angle-Resolved Photoemission. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 156 p.

Source: Dissertations Abstracts International, Volume: 80-09, Section: B.

Thesis (Ph.D.)--University of California, Davis, 2018.

This item must not be sold to any third party vendors.

The invention of the transistor revolutionized the world by allowing advances that could hardly be imagined only a few decades earlier. Their pervasiveness in almost every imaginable device today, ranging from wristwatches to large scale industrial automation components, shows just how significant a building block of the modern world transistors are. It also underlines the significance of any potential further advances in semiconductor technology. An emerging development in this regard is the addition of magnetic properties to semiconductors, which, among other things, has the potential of enabling a significant increase in computer storage capacity as well as a corresponding cost decrease. The ability to combine the nonvolatile nature of magnetic materials with the fast speeds typical of semiconductor devices could provide a path to a dramatic improvement of storage technology. A new class of materials suggested to have both semiconductor and magnetic properties is known as dilute magnetic semiconductors (DMS). The main focus of this thesis is the study of the dilute magnetic semiconductor of the group III-V, Ga(Mn)P, which consists of GaP that is doped with metal Manganese. Ga(Mn)P is closely related to Ga(Mn)As which has received a lot of attention in the materials science community. There are, however, important differences between Ga(Mn)P and Ga(Mn)As which we will discuss in this thesis. The electronic structure of three different Ga1-xMn xP DMSs is investigated, with x representing the percent dopant of Mn, which is substitutional to Ga. The three dopant samples are Ga0.98Mn 0.02P, Ga0.968Mn0.032P, and Ga0.959Mn 0.041P and they are compared to the undoped GaP sample. The experiments reported in this thesis were performed at a number of synchrotron facilities, namely the Advanced Light Source (ALS) at Berkeley (USA), SOLEIL in Paris (France), and SPring-8 at Hyogo (Japan). All these facilities are third-generation synchrotrons. Hard X-ray photoelectron spectroscopy (HXPS) and hard X-ray angle-resolved photoemission spectroscopy (HARPES) at energies of about 3 keV, were the methods used to study the electronic structure of the samples. The advantage of hard x-ray photoelectron spectroscopy is the ability to probe deeper into the sample, therefore measuring bulk properties of the materials. In order to understand the role of the Mn dopant in the emergence of ferromagnetism in our samples, we present both experimental data and theoretical calculations. Both core-level spectra and angle-resolved or angle-integrated valence spectra of Ga0.98Mn0.02P and the undoped GaP are discussed. In particular, the HARPES experimental data are compared to free-electron final-state model calculations and to more accurate one-step photoemission theory. The experimental results show differences between Ga 0.98Mn0.02P and GaP in both angle-resolved and angle-integrated valence spectra. The Ga0.98Mn0.02P bands are broadened due to the presence of Mn impurities that disturb the long-range translational order of the host GaP crystal. Mn-induced changes of the electronic structure are observed over the entire valence band range, including the presence of a distinct impurity band close to the valence-band maximum of the DMS. These experimental results are in good agreement with the one-step photoemission calculations, and a prior HARPES study of Ga0.97Mn0.03As and GaAs (Gray et al. Nature Materials 11, 957 (2012)), demonstrating the strong similarity between these two materials. The Mn 2p and 3s core-level spectra also reveal an essentially identical state in doping both GaAs and GaP. Furthermore, additional HXPS experimental results for all three dopant concentrations at two different photon energies, 2550 eV and 2905 eV, show a detailed study of various core-levels. Ga 2p, Ga 3 d, P 2p, Mn 2p, and Mn 3 s are the main core-levels analyzed and all their features such as spin-orbit splitting, multiplet splitting, and satellite are explained. Experimental data is compared to theoretical calculations using the simulation of electron spectra of surface analysis (SESSA) program.

ISBN: 9780438930964Subjects--Topical Terms:

3173567
Condensed matter physics.

Study of the Dilute Magnetic Semiconductor, Ga1-x MnxP and undoped GaP, with Hard X-Ray Photoemission and Angle-Resolved Photoemission.
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245 1 0 $a Study of the Dilute Magnetic Semiconductor, Ga1-x MnxP and undoped GaP, with Hard X-Ray Photoemission and Angle-Resolved Photoemission.
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500 $a Source: Dissertations Abstracts International, Volume: 80-09, Section: B.
500 $a Publisher info.: Dissertation/Thesis.
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502 $a Thesis (Ph.D.)--University of California, Davis, 2018.
506 $a This item must not be sold to any third party vendors.
520 $a The invention of the transistor revolutionized the world by allowing advances that could hardly be imagined only a few decades earlier. Their pervasiveness in almost every imaginable device today, ranging from wristwatches to large scale industrial automation components, shows just how significant a building block of the modern world transistors are. It also underlines the significance of any potential further advances in semiconductor technology. An emerging development in this regard is the addition of magnetic properties to semiconductors, which, among other things, has the potential of enabling a significant increase in computer storage capacity as well as a corresponding cost decrease. The ability to combine the nonvolatile nature of magnetic materials with the fast speeds typical of semiconductor devices could provide a path to a dramatic improvement of storage technology. A new class of materials suggested to have both semiconductor and magnetic properties is known as dilute magnetic semiconductors (DMS). The main focus of this thesis is the study of the dilute magnetic semiconductor of the group III-V, Ga(Mn)P, which consists of GaP that is doped with metal Manganese. Ga(Mn)P is closely related to Ga(Mn)As which has received a lot of attention in the materials science community. There are, however, important differences between Ga(Mn)P and Ga(Mn)As which we will discuss in this thesis. The electronic structure of three different Ga1-xMn xP DMSs is investigated, with x representing the percent dopant of Mn, which is substitutional to Ga. The three dopant samples are Ga0.98Mn 0.02P, Ga0.968Mn0.032P, and Ga0.959Mn 0.041P and they are compared to the undoped GaP sample. The experiments reported in this thesis were performed at a number of synchrotron facilities, namely the Advanced Light Source (ALS) at Berkeley (USA), SOLEIL in Paris (France), and SPring-8 at Hyogo (Japan). All these facilities are third-generation synchrotrons. Hard X-ray photoelectron spectroscopy (HXPS) and hard X-ray angle-resolved photoemission spectroscopy (HARPES) at energies of about 3 keV, were the methods used to study the electronic structure of the samples. The advantage of hard x-ray photoelectron spectroscopy is the ability to probe deeper into the sample, therefore measuring bulk properties of the materials. In order to understand the role of the Mn dopant in the emergence of ferromagnetism in our samples, we present both experimental data and theoretical calculations. Both core-level spectra and angle-resolved or angle-integrated valence spectra of Ga0.98Mn0.02P and the undoped GaP are discussed. In particular, the HARPES experimental data are compared to free-electron final-state model calculations and to more accurate one-step photoemission theory. The experimental results show differences between Ga 0.98Mn0.02P and GaP in both angle-resolved and angle-integrated valence spectra. The Ga0.98Mn0.02P bands are broadened due to the presence of Mn impurities that disturb the long-range translational order of the host GaP crystal. Mn-induced changes of the electronic structure are observed over the entire valence band range, including the presence of a distinct impurity band close to the valence-band maximum of the DMS. These experimental results are in good agreement with the one-step photoemission calculations, and a prior HARPES study of Ga0.97Mn0.03As and GaAs (Gray et al. Nature Materials 11, 957 (2012)), demonstrating the strong similarity between these two materials. The Mn 2p and 3s core-level spectra also reveal an essentially identical state in doping both GaAs and GaP. Furthermore, additional HXPS experimental results for all three dopant concentrations at two different photon energies, 2550 eV and 2905 eV, show a detailed study of various core-levels. Ga 2p, Ga 3 d, P 2p, Mn 2p, and Mn 3 s are the main core-levels analyzed and all their features such as spin-orbit splitting, multiplet splitting, and satellite are explained. Experimental data is compared to theoretical calculations using the simulation of electron spectra of surface analysis (SESSA) program.
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650 4 $a Materials science. $3 543314
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