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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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Magnetic origins of epitaxial MAX phase Mn2GaC-based thin films probed by Emission Mössbauer Spectroscopy
/ Qi, Bingcui (Science Institute, University of Iceland, Iceland) ; Gunnlaugsson, Haraldur Páll (Science Institute, University of Iceland, Iceland) ; Ólafsson, Sveinn (Science Institute, University of Iceland, Iceland) ; Þorsteinsson, Einar Baldur (Science Institute, University of Iceland, Iceland) ; Magnus, Friðrik (Science Institute, University of Iceland, Iceland) ; Rosén, Johanna (Materials Design Division, Department of Physics, Chemistry and Biology, IFM, Linköping University, Linköping 58183, Sweden) ; Tao, Quanzheng (Materials Design Division, Department of Physics, Chemistry and Biology, IFM, Linköping University, Linköping 58183, Sweden) ; Mantovan, Roberto (3CNR-IMM, Unit of Agrate Brianza, Via C. Olivetti 2, 20864 Agrate Brianza (MB), Italy) ; Masenda, Hilary (School of Physics, University of the Witwatersrand, South Africa) ; Zyabkin, Dmitry (Ilmenau, Gustav-Kirchhoff-Strasse 5, 98693 Ilmenau, Germany) et al.
CERN-INTC-2024-017 ; INTC-P-696.
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2024.
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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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Anisotropy of the Electric Field Gradient in Two-Dimensional α-MoO$_3$ Investigated by $^{57}$Mn($^{57}$Fe) Emission Mössbauer Spectroscopy
/ Schell, Juliana (CERN ; Duisburg-Essen U.) ; Zyabkin, Dmitry (Ilmenau Tech. U.) ; Bharuth-Ram, Krish (KwaZulu Natal U.) ; Gonçalves, João N (Aveiro U.) ; Díaz-Guerra, Carlos (Madrid U.) ; Gunnlaugsson, Haraldur P (Iceland U.) ; Martín-Luengo, Aitana Tarazaga (Linz U.) ; Schaaf, Peter (Ilmenau Tech. U.) ; Bonanni, Alberta (Linz U.) ; Masenda, Hilary (Witwatersrand U. ; Philipps U. Marburg) et al.
Van der Waals α-MoO3 samples offer a wide range of attractive catalytic, electronic, and optical properties. We present herein an emission Mössbauer spectroscopy (eMS) study of the electric-field gradient (EFG) anisotropy in crystalline free-standing α-MoO3 samples. [...]
2022 - 13 p.
- Published in : Crystals 12 (2022) 942
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Charge and spin state of dilute Fe in NaCl and LiF
/ ISOLDE Collaboration
There is an apparent mismatch between electron paramagnetic resonance and Mössbauer spectroscopy results on the charge and spin states of dilute Fe impurities in NaCl; Mössbauer spectroscopy data have been interpreted in terms of high-spin Fe$^{2+}$, while electron paramagnetic resonance studies suggest low-spin Fe$^{1+}$. In the present study, the charge and spin states of dilute substitutional Fe impurities in NaCl and LiF have been investigated with $^{57}$Mn → $^{57}$Fe emission Mössbauer spectroscopy. [...]
2022 - 10 p.
- Published in : Phys. Rev. B 106 (2022) 174108
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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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Magnetic Structure and Strain State in Fe/V Superlattices Studied by $^{57}$Fe$^+$ Emission and Conversion Electron Mössbauer Spectroscopy
/ Mølholt, Torben E (Iceland U. ; CERN) ; Ólafsson, Sveinn (Iceland U.) ; Gunnlaugsson, Haraldur P (Iceland U.) ; Qi, Bingcui (Iceland U.) ; Johnston, Karl (CERN) ; Mantovan, Roberto (IMM, Bologna) ; Masenda, Hilary (Witwatersrand U.) ; Bharuth-Ram, Krish (DUT, Durban) ; Gíslason, Hafliði P (Iceland U.) ; Langouche, Guido (Leuven U.) et al.
The magnetic properties of the Fe/V superlattices were studied by conventional Conversion Electron Mössbauer Spectroscopy (CEMS) and online 57Fe+ emission Mössbauer Spectroscopy (eMS) at room temperature (RT) at ISOLDE/CERN. The unique depth-enhanced sensitivity and ultradiluted regime of the probe atoms adopted in this eMS facility enabled the investigation of the magnetic structures and the strain state in the superlattice layers and at the interfaces. [...]
2022 - 15 p.
- Published in : Crystals 12 (2022) 961
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Metal-insulator transition in crystalline V$_2$O$_3$ thin films probed at atomic-scale using emission Mössbauer spectroscopy
/ Qi, B (Iceland U.) ; Gunnlaugsson, H P (Iceland U.) ; Ólafsson, S (Iceland U.) ; Gislason, H P (Iceland U.) ; Thorsteinsson, E B (Iceland U.) ; Arnalds, U B (Iceland U.) ; Mantovan, R (CNR-IMM, Catania) ; Unzueta l, I (Basque U., Bilbao) ; Zyabkin, D V (Ilmenau Tech. U.) ; Bharuth Ram, K (KwaZulu Natal U. ; DUT, Durban) et al.
Microscopic understanding the metal-to-insulator transition (MIT) in strongly correlated materials is critical to
the design and control of modern “beyond silicon” Mott nanodevices. In this work, the local MIT behaviors in
single crystalline V$_2$O$_3$ thin films were probed on an atomic scale by online $^{57}$Fe emission Mössbauer spectroscopy (eMS) following dilute ($<10^{-3}$ at.%) implantation of $^{57}$Mn$^+$ (T$_{1/2}$ = 90 s). [...]
2020
- Published in : Thin Solid Films 714 (2020) 138389
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Experimental and Theoretical Study of Electronic and Hyperfine Properties of Hydrogenated Anatase (TiO2): Defect Interplay and Thermal Stability
/ Zyabkin, D V (Palacky U. ; Ilmenau Tech. U.) ; Gunnlaugsson, H P (Iceland U.) ; Gonçalves, J N (Aveiro U.) ; Bharuth-Ram, K (KwaZulu Natal U. ; DUT, Durban) ; Qi, B (Iceland U.) ; Unzueta, I (Basque U., Bilbao) ; Naidoo, D (Witwatersrand U.) ; Mantovan, R (CNR-IMM, Catania) ; Masenda, H (Witwatersrand U.) ; Ólafsson, S (Iceland U.) et al.
The performance of TiO$_2$-based materials is highly dependent on the electronic structure and local defect configurations. Hence, a thorough understanding of defect interaction plays a key role. [...]
2020 - 12 p.
- Published in : The Journal of Physical Chemistry C 124 (2020) 7511-7522
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Annealing studies combined with low temperature emission Mössbauer spectroscopy of short-lived parent isotopes: Determination of local Debye–Waller factors
/ Gunnlaugsson, H P (Iceland U.) ; Masenda, H (U. Witwatersrand, Johannesburg, Sch. Phys.) ; Mølholt, T E (Denmark, Tech. U.) ; Bharuth-Ram, K (KwaZulu Natal U. ; DUT, Durban) ; Ólafsson, S (Iceland U.) ; Johnston, K (CERN) ; Schell, J (CERN ; Duisburg-Essen U.) ; Gislason, H P (Iceland U.) ; Krastev, P B (Sofiya, Inst. Nucl. Res.) ; Mantovan, R (SGS Thomson, Milan) et al.
An extension of the online implantation chamber used for emission Mössbauer Spectroscopy (eMS) at ISOLDE/CERN that allows for quick removal of samples for offline low temperature studies is briefly described. We demonstrate how online eMS data obtained during implantation at temperatures between 300 K and 650 K of short-lived parent isotopes combined with rapid cooling and offline eMS measurements during the decay of the parent isotope can give detailed information on the binding properties of the Mössbauer probe in the lattice. [...]
2021
- Published in : Rev. Sci. Instrum. 92 (2021) 013901
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