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Compositional Dependence of Epitaxial
L
1
0
‐Mn
x
Ga Magnetic Properties as Probed by
57
Mn/Fe and
119
In/Sn Emission Mössbauer Spectroscopy
/ Unzueta, Iraultza (Basque U., Bilbao) ; Gunnlaugsson, Haraldur Pall (Iceland U.) ; Mølholt, Torben Esmann (CERN) ; Masenda, Hilary (U. Witwatersrand, Johannesburg, Sch. Phys.) ; Mokhles Gerami, Adeleh (IPM, Tehran) ; Krastev, Petko (Sofiya, Inst. Nucl. Res.) ; Zyabkin, Dmitry V (Ilmenau Tech. U.) ; Bharuth-Ram, Krish (KwaZulu Natal U.) ; Naidoo, Deena (U. Witwatersrand, Johannesburg, Sch. Phys.) ; Ólafsson, Sveinn (Iceland U.) et al.
The magnetic properties of MnxGa alloys critically depend on compositionx, andthe atomic-scale origin of those dependences is still not fully disclosed. Molecularbeam epitaxy has been used to produce a set of MnxGa samples (x¼0.7÷1.9)with strong perpendicular magnetic anisotropy, and controllable saturationmagnetization and coercivefield depending onx. [...]
2022 - 11 p.
- Published in : Phys. Status Solidi B 259 (2022) 2200121
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2.
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Temperature and dose dependence of defect complex formation with ion implanted Mn/Fe in ZnO
/ Mølholt, T E (Iceland U.) ; Mantovan, R (MDM Observ.) ; Gunnlaugsson, H P (Aarhus U.) ; Bharuth-Ram, K (iThemba LABS) ; Fanciulli, M (MDM Observ. ; Milan Bicocca U.) ; Gíslason, H P (Iceland U.) ; Johnston, K (CERN) ; Kobayashi, Y (Wako, RIKEN) ; Langouche, G (Leuven U.) ; Masenda, H (Witwatersrand U.) et al.
57Fe Mössbauer spectroscopy following ion implantation of radioactive 57Mn+ ( T1/2=85.4 s) has been applied to study the formation of Fe/Mn implantation-induced defects in ZnO at temperatures between 319 and 390 K. The formation of ferric iron–vacancy complexes is found to depend strongly on the implanted dose and to be faster and more efficient at higher temperatures [...]
2009
- Published in : Physica B 404 (2009) 4820-4822
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3.
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Local increase of the Curie temperature in Mn/Fe implanted Y$_{3}$Fe$_{5}$O$_{12}$ (YIG)
/ Krastev, P B (Sofiya, Inst. Nucl. Res.) ; Gunnlaugsson, H P (Iceland U.) ; Nomura, K (Tokyo Metropolitan U.) ; Bharuth-Ram, K (DUT, Durban ; KwaZulu Natal U.) ; Qi, B (Iceland U.) ; Masenda, H (Witwatersrand U.) ; Mølholt, T E (Roskilde U., IMFUFA ; CERN) ; Naidoo, D (Witwatersrand U.) ; Ólafsson, S (Iceland U.) ; Tarazaga Martín-Luengo, A (Linz U.) et al.
The change in the Curie temperature of single crystalline garnet Y$_{3}$Fe$_{5}$O$_{12}$ (YIG) sample due to lattice damage induced by ion implantation has been investigated in $^{57}$Fe emission Mössbauer Spectroscopy (eMS) following implantation of $^{57}$Mn (T½=1.5 min). The Mössbauer spectra analysis reveal high spin Fe $^{3+}$ ions substituted on both the octahedral and the tetrahedral sites. [...]
2020
- Published in : Appl. Radiat. Isot. 160 (2020) 109121
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4.
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Emission Mössbauer spectroscopy study of fluence dependence of paramagnetic relaxation in Mn/Fe implanted ZnO
/ Masenda, H (Witwatersrand U.) ; Geburt, S (Institute of Solid State PhysicsUniversity of JenaJenaGermany ; Jena U.) ; Bharuth-Ram, K (DUT, Durban ; KwaZulu Natal U.) ; Naidoo, D (Witwatersrand U.) ; Gunnlaugsson, H P (CERN ; Leuven U.) ; Johnston, K (CERN) ; Mantovan, R (IMM-CNR, Brianza) ; Mølholt, T E (CERN) ; Ncube, M (Witwatersrand U.) ; Shayestehaminzadeh, S (RWTH Aachen U.) et al.
/ISOLDE
Emission Mössbauer Spectroscopy following the implantation of radioactive precursor isotope $^{57}$Mn$^{+}$ (T$_{1/2}$= 1.5 min) into ZnO single crystals at ISOLDE/CERN shows that a large fraction of $^{57}$Fe atoms produced in the $^{57}$Mn beta decay is created as paramagnetic Fe$^{3+}$ with relatively long spin-lattice relaxation times. Here we report on ZnO pre-implanted with $^{56}$Fe to fluences of 2×10$^{13}$, 5×10$^{13}$ and 8 × 10$^{13}$ ions/cm2 in order to investigate the dependence of the paramagnetic relaxation rate of Fe$^{3+}$ on fluence. [...]
2016 - 7 p.
- Published in : Hyperfine Interact. 237 (2016) 40
Fulltext: PDF; External link: Link to fulltext on ICAME2015 document server
In : International Conference on the Applications of the Mössbauer Effect, Hamburg, Germany, 13 - 18 Sep 2015, pp.40
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5.
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$^{57}$Fe Mössbauer study of epitaxial TiN thin film grown on MgO (1 0 0) by magnetron sputtering
/ Qi, B (Iceland U.) ; Gunnlaugsson, H P (Iceland U.) ; Mokhles Gerami, A (K.N. Toosi U.) ; Gislason, H P (Iceland U.) ; Ólafsson, S (Iceland U.) ; Magnus, F (Iceland U.) ; Mølholt, T E (CERN) ; Masenda, H (U. Witwatersrand, Johannesburg, Sch. Phys.) ; Tarazaga Martín-Lueugo, A (Linz U.) ; Bonanni, A (Linz U.) et al.
/ISOLDE
The properties and performance of TiN thin films are closely related to the concentration and mobility of lattice defects in the thin film structures of TiN. This makes a local atomic scale study of TiN thin films an ever-growing demand. [...]
2019 - 10 p.
- Published in : Appl. Surf. Sci. 464 (2019) 682-691
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6.
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Lattice sites, charge states and spin–lattice relaxation of Fe ions in 57Mn+ implanted GaN and AlN
/ Masenda, H (U. Witwatersrand, Johannesburg, Sch. Phys.) ; Naidoo, D (U. Witwatersrand, Johannesburg, Sch. Phys.) ; Bharuth-Ram, K (DUT, Durban ; iThemba LABS) ; Gunnlaugsson, H P (CERN ; KU Leuven, Dept. Phys. Astron.) ; Johnston, K (CERN) ; Mantovan, R (CNR-IMM Agrate Brianza, Italy) ; Mølholt, T E (CERN) ; Ncube, M (U. Witwatersrand, Johannesburg, Sch. Phys.) ; Shayestehaminzadeh, S (RWTH Aachen U.) ; Gíslason, H P (Iceland U.) et al.
The lattice sites, valence states, resulting magnetic behaviour and spin–lattice relaxation of Fe ions in GaN and AlN were investigated by emission Mössbauer spectroscopy following the implantation of radioactive $^{57}Mn^+$ ions at ISOLDE/CERN. Angle dependent measurements performed at room temperature on the 14.4 keV γ-rays from the 57Fe Mössbauer state (populated from the $^{57}$Mn $β ^−$ decay) reveal that the majority of the Fe ions are in the 2+ valence state nearly substituting the Ga and Al cations, and/or associated with vacancy type defects. [...]
2016 - 9 p.
- Published in : J. Magn. Magn. Mater. 401 (2016) 1130-1138
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7.
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Unusual charge states and lattice sites of Fe in Al$_{x}$Ga$_{1−x}$N:Mn
/ Masenda, Hilary (Witwatersrand U. ; Philipps U. Marburg) ; Gunnlaugsson, Haraldur Páll (Iceland U.) ; Adhikari, Rajdeep (Linz U.) ; Bharuth-Ram, Krish (DUT, Durban) ; Naidoo, Deena (Witwatersrand U.) ; Tarazaga Martín-Luengo, Aitana (Linz U.) ; Unzueta, Iraultza (Basque U., Bilbao) ; Mantovan, Roberto (CNR-IMM, Catania) ; Mølholt, Torben Esmann (CERN) ; Johnston, Karl (CERN) et al.
Charge states and lattice sites of Fe ions in virgin and Mn-doped Al$_{x}$Ga$_{1−x}$N samples were investigated using $^{57}$Fe emission Mössbauer spectroscopy following radioactive $^{57}$Mn$^{+}$ ion implantation at ISOLDE, CERN. In the undoped Al$_{x}$Ga$_{1−x}$N, Fe$^{2+}$ on Al/Ga sites associated with nitrogen vacancies and Fe$^{3+}$ on substitutional Al/Ga sites are identified. [...]
2022 - 12 p.
- Published in : New J. Phys. 24 (2022) 103007
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8.
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Temperature Dependence of the Hyperfine Magnetic Field at Fe Sites in Ba-Doped BiFeO$_3$ Thin Films Studied by Emission Mössbauer Spectroscopy
/ Heiniger-Schell, Juliana (CERN ; Duisburg-Essen U.) ; Bharuth-Ram, Krish (ENS, Lyon, Lab. Phys. ; KwaZulu Natal U. ; DUT, Durban) ; Naicker, Kimara (ENS, Lyon, Lab. Phys. ; KwaZulu Natal U.) ; Masondo, Vusumuzi (DUT, Durban) ; Dang, Thien Thanh (Duisburg-Essen U.) ; Escobar, Marianela (Duisburg-Essen U.) ; Díaz-Guerra, Carlos (Madrid U.) ; Marschick, Georg (Vienna, Tech. U.) ; Masenda, Hilary (Witwatersrand U.) ; Gunnlaugsson, Haraldur P (Iceland U.) et al.
Emission $^{57}$Fe Mössbauer spectroscopy (eMS), following the implantation of radioactive $^{57}$Mn+ ions, has been used to study the temperature dependence of the hyperfine magnetic field at Fe sites in Ba-doped BiFeO$_3$ (BFO) thin films. $^{57}$Mn β decays (t$_{1/2}$ = 90 s) to the 14.4 keV Mössbauer state of $^{57}$Fe, thus allowing online eMS measurements at a selection of sample temperatures during Mn implantation. [...]
2023 - 13 p.
- Published in : Crystals 13 (2023) 724
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9.
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Charge states of transition metal ions and local magnetic structure of dilute magnetic semiconductor (Ga,Fe)N:Mn - an emission Mossbauer spectroscopy study
- ISOLDE.
Approved: 06 March 2024.-
Status: Preparation
External link: Experiment home page
Experiment: IS751
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10.
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Paramagnetism in Mn/Fe implanted ZnO
/ Gunnlaugsson, HP (Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark.) ; Fanciulli, M (CNR IMM MDM Lab, I-20041 Agrate Brianza, MB, Italy. ; Univ Milano Bicocca, Dept Mat Sci, I-20125 Milan, Italy.) ; Weyer, G (Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark.) ; Kobayashi, Y (RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan.) ; Bharuth-Ram, K (Univ KwaZulu Natal, Sch Phys, ZA-4001 Durban, South Africa. ; iThemba Labs, ZA-7129 Somerset W, South Africa.) ; Olafsson, S (Univ Iceland, Inst Sci, IS-107 Reykjavik, Iceland.) ; Gislason, H P (Univ Iceland, Inst Sci, IS-107 Reykjavik, Iceland.) ; Gunnlaugsson, H P (Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark.) ; Yoshida, Y (Shizuoka Inst Sci & Technol, Shizuoka 4378555, Japan.) ; Langouche, G (Univ Louvain, Inst Kern En Stralings Fys, B-3001 Louvain, Belgium.) et al.
Prompted by the generally poor understanding of the nature of magnetic phenomena in 3d-metal doped ZnO, we have undertaken on-line Fe-57 Mossbauer spectroscopy on ZnO single crystals in an external magnetic field of 0.6 T, following the implantation of radioactive Mn-57 ions at room temperature. The Mossbauer spectra of the dilute Fe impurities are dominated by sextets whose angular dependence rules out an ordered magnetic state (which had been previously proposed) but are well accounted for on the basis of Fe3+ paramagnetic centers on substitutional Zn sites with unusually long relaxation times (> 20 ns) [...]
2010
- Published in : Appl. Phys. Lett. 97 (2010) 142501
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