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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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2.
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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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3.
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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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4.
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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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5.
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Sensitivity of $^{57}$Fe emission Mössbauer spectroscopy to Ar and C induced defects in ZnO
/ Bharuth-Ram, K (DUT, Durban) ; Mølholt, T E (CERN) ; Langouche, G (Leuven U.) ; Geburt, S (U. Jena (main)) ; Ronning, C (U. Jena (main)) ; Doyle, T B (iThemba LABS ; KwaZulu Natal U.) ; Gunnlaugsson, H P (CERN) ; Johnston, K (CERN) ; Mantovan, R (IMM-CNR, Brianza) ; Masenda, H (Witwatersrand U.) et al.
/Isolde
Emission Mössbauer Spectroscopy (eMS) measurements, following low fluence (<1012 cm−2) implantation of 57Mn (t 1/2 = 1.5 min.) into ZnO single crystals pre-implanted with Ar and C ions, has been utilized to test the sensitivity of the 57Fe eMS technique to the different types of defects generated by the different ion species. The dominant feature of the Mössbauer spectrum of the Ar implanted ZnO sample was a magnetic hyperfine field distribution component, attributed to paramagnetic Fe3+, while that of the C implanted sample was a doublet attributed to substitutional Fe2+ forming a complex with the C dopant ions in the 2− state at O vacancies. [...]
2016
- Published in : Hyperfine Interact. 237 (2016) 81
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.81
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6.
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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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7.
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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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8.
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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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9.
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10.
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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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