TY  - JOUR
AU  - Di Capua, Roberto
AU  - Verma, Manish
AU  - Radović, Milan
AU  - Plumb, Nicholas C.
AU  - Dil, Jan Hugo
AU  - Ristić, Zoran
AU  - Guedes, Eduardo Bonini
AU  - de Luca, Giovanna
AU  - Preziosi, Daniele
AU  - Wang, Zhiming
AU  - Weber, Andrew P.
AU  - Pentcheva, Rossitza
AU  - Salluzzo, Marco
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10118
AB  - Studies on oxide quasi-two-dimensional electron gas (q2DEG) have been a playground for the discovery of novel and sometimes unexpected phenomena, like the reported magnetism at the surface of SrTiO3 (001) and at the interface between nonmagnetic LaAlO3 and SrTiO3 band insulators. However, magnetism in this system is weak and there is evidence of a nonintrinsic origin. Here, by using in situ high-resolution angle-resolved photoemission, we demonstrate that ferromagnetic EuTiO3, the magnetic counterpart of SrTiO3 in the bulk, hosts a q2DEG at its (001) surface. This is confirmed by density functional theory calculations with Hubbard U terms in the presence of oxygen divacancies in various configurations, all of them leading to a spin-polarized q2DEG related to the ferromagnetic order of Eu-4f magnetic moments. The results suggest EuTiO3(001) as a new material platform for oxide q2DEGs, characterized by broken inversion and time-reversal symmetries.
T2  - Physical Review Research
T1  - Two-dimensional electron gas at the (001) surface of ferromagnetic EuTiO3
VL  - 3
IS  - 4
SP  - L042038
DO  - 10.1103/PhysRevResearch.3.L042038
ER  - 

@article{
author = "Di Capua, Roberto and Verma, Manish and Radović, Milan and Plumb, Nicholas C. and Dil, Jan Hugo and Ristić, Zoran and Guedes, Eduardo Bonini and de Luca, Giovanna and Preziosi, Daniele and Wang, Zhiming and Weber, Andrew P. and Pentcheva, Rossitza and Salluzzo, Marco",
year = "2021",
abstract = "Studies on oxide quasi-two-dimensional electron gas (q2DEG) have been a playground for the discovery of novel and sometimes unexpected phenomena, like the reported magnetism at the surface of SrTiO3 (001) and at the interface between nonmagnetic LaAlO3 and SrTiO3 band insulators. However, magnetism in this system is weak and there is evidence of a nonintrinsic origin. Here, by using in situ high-resolution angle-resolved photoemission, we demonstrate that ferromagnetic EuTiO3, the magnetic counterpart of SrTiO3 in the bulk, hosts a q2DEG at its (001) surface. This is confirmed by density functional theory calculations with Hubbard U terms in the presence of oxygen divacancies in various configurations, all of them leading to a spin-polarized q2DEG related to the ferromagnetic order of Eu-4f magnetic moments. The results suggest EuTiO3(001) as a new material platform for oxide q2DEGs, characterized by broken inversion and time-reversal symmetries.",
journal = "Physical Review Research",
title = "Two-dimensional electron gas at the (001) surface of ferromagnetic EuTiO3",
volume = "3",
number = "4",
pages = "L042038",
doi = "10.1103/PhysRevResearch.3.L042038"
}

Di Capua, R., Verma, M., Radović, M., Plumb, N. C., Dil, J. H., Ristić, Z., Guedes, E. B., de Luca, G., Preziosi, D., Wang, Z., Weber, A. P., Pentcheva, R.,& Salluzzo, M.. (2021). Two-dimensional electron gas at the (001) surface of ferromagnetic EuTiO3. in Physical Review Research, 3(4), L042038.
https://doi.org/10.1103/PhysRevResearch.3.L042038

Di Capua R, Verma M, Radović M, Plumb NC, Dil JH, Ristić Z, Guedes EB, de Luca G, Preziosi D, Wang Z, Weber AP, Pentcheva R, Salluzzo M. Two-dimensional electron gas at the (001) surface of ferromagnetic EuTiO3. in Physical Review Research. 2021;3(4):L042038.
doi:10.1103/PhysRevResearch.3.L042038 .

Di Capua, Roberto, Verma, Manish, Radović, Milan, Plumb, Nicholas C., Dil, Jan Hugo, Ristić, Zoran, Guedes, Eduardo Bonini, de Luca, Giovanna, Preziosi, Daniele, Wang, Zhiming, Weber, Andrew P., Pentcheva, Rossitza, Salluzzo, Marco, "Two-dimensional electron gas at the (001) surface of ferromagnetic EuTiO3" in Physical Review Research, 3, no. 4 (2021):L042038,
https://doi.org/10.1103/PhysRevResearch.3.L042038 . .

TY  - JOUR
AU  - Muff, Stefan
AU  - Pilet, Nicolas
AU  - Fanciulli, Mauro
AU  - Weber, Andrew P.
AU  - Wessler, Christian
AU  - Ristić, Zoran
AU  - Wang, Zhiming
AU  - Plumb, Nicholas C.
AU  - Radović, Milan
AU  - Dil, J. Hugo
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11084
AB  - The electronic structure of in situ grown ferroelectric BaTiO3(001) films is studied by angle-resolved photoemission spectroscopy. A two-dimensional state is found at the film-vacuum interface with an unexpected checkerboardlike Fermi surface. The observed absence of in-plane dispersion of the states is attributed to the influence of the strong electric fields of the ferroelectric bulk of the film. These fields cause Bloch oscillations and Wannier-Stark localization of free charges in real space, resulting in a smearing in reciprocal space. It is shown that this effect extends to thin SrTiO3 overlayers grown on the BaTiO3 film.
PB  - American Physical Society (APS)
T2  - Physical Review B
T1  - Influence of ferroelectric order on the surface electronic structure of BaTiO3 films studied by photoemission spectroscopy
VL  - 98
IS  - 4
SP  - 045132
DO  - 10.1103/PhysRevB.98.045132
ER  - 

@article{
author = "Muff, Stefan and Pilet, Nicolas and Fanciulli, Mauro and Weber, Andrew P. and Wessler, Christian and Ristić, Zoran and Wang, Zhiming and Plumb, Nicholas C. and Radović, Milan and Dil, J. Hugo",
year = "2018",
abstract = "The electronic structure of in situ grown ferroelectric BaTiO3(001) films is studied by angle-resolved photoemission spectroscopy. A two-dimensional state is found at the film-vacuum interface with an unexpected checkerboardlike Fermi surface. The observed absence of in-plane dispersion of the states is attributed to the influence of the strong electric fields of the ferroelectric bulk of the film. These fields cause Bloch oscillations and Wannier-Stark localization of free charges in real space, resulting in a smearing in reciprocal space. It is shown that this effect extends to thin SrTiO3 overlayers grown on the BaTiO3 film.",
publisher = "American Physical Society (APS)",
journal = "Physical Review B",
title = "Influence of ferroelectric order on the surface electronic structure of BaTiO3 films studied by photoemission spectroscopy",
volume = "98",
number = "4",
pages = "045132",
doi = "10.1103/PhysRevB.98.045132"
}

Muff, S., Pilet, N., Fanciulli, M., Weber, A. P., Wessler, C., Ristić, Z., Wang, Z., Plumb, N. C., Radović, M.,& Dil, J. H.. (2018). Influence of ferroelectric order on the surface electronic structure of BaTiO3 films studied by photoemission spectroscopy. in Physical Review B
American Physical Society (APS)., 98(4), 045132.
https://doi.org/10.1103/PhysRevB.98.045132

Muff S, Pilet N, Fanciulli M, Weber AP, Wessler C, Ristić Z, Wang Z, Plumb NC, Radović M, Dil JH. Influence of ferroelectric order on the surface electronic structure of BaTiO3 films studied by photoemission spectroscopy. in Physical Review B. 2018;98(4):045132.
doi:10.1103/PhysRevB.98.045132 .

Muff, Stefan, Pilet, Nicolas, Fanciulli, Mauro, Weber, Andrew P., Wessler, Christian, Ristić, Zoran, Wang, Zhiming, Plumb, Nicholas C., Radović, Milan, Dil, J. Hugo, "Influence of ferroelectric order on the surface electronic structure of BaTiO3 films studied by photoemission spectroscopy" in Physical Review B, 98, no. 4 (2018):045132,
https://doi.org/10.1103/PhysRevB.98.045132 . .

TY  - JOUR
AU  - Muff, Steffan
AU  - Fanciulli, Mauro
AU  - Weber, Andrew P.
AU  - Pilet, Nicolas
AU  - Ristić, Zoran
AU  - Wang, Zhiming
AU  - Plumb, Nicholas C.
AU  - Radović, Milan
AU  - Dil, J. Hugo
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7194
AB  - The two-dimensional electron gas at the surface of titanates gathered attention due to its potential to replace conventional silicon based semiconductors in the future. In this study, we investigated films of the parent perovskite CaTiO3, grown by pulsed laser deposition, by means of angular-resolved photoelectron spectroscopy. The films show a c(4 x 2) surface reconstruction after the growth that is reduced to a p(2 x 2) reconstruction under UV-light. At the CaTiO3 film surface, a two-dimensional electron gas (2DEG) is found with an occupied band width of 400 meV. With our findings CaTiO3 is added to the group of oxides witha 2DEG at their surface. Our study widens the phase space to investigate strontium and barium doped CaTiO3 and the interplay of ferroelectric properties with the 2DEG at oxide surfaces. This could open up new paths to tailor two-dimensional transport properties of these systems towards possible applications. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - Observation of a two-dimensional electron gas at CaTiO3 film surfaces
VL  - 432
SP  - 41
EP  - 45
DO  - 10.1016/j.apsusc.2017.05.229
ER  - 

@article{
author = "Muff, Steffan and Fanciulli, Mauro and Weber, Andrew P. and Pilet, Nicolas and Ristić, Zoran and Wang, Zhiming and Plumb, Nicholas C. and Radović, Milan and Dil, J. Hugo",
year = "2018",
abstract = "The two-dimensional electron gas at the surface of titanates gathered attention due to its potential to replace conventional silicon based semiconductors in the future. In this study, we investigated films of the parent perovskite CaTiO3, grown by pulsed laser deposition, by means of angular-resolved photoelectron spectroscopy. The films show a c(4 x 2) surface reconstruction after the growth that is reduced to a p(2 x 2) reconstruction under UV-light. At the CaTiO3 film surface, a two-dimensional electron gas (2DEG) is found with an occupied band width of 400 meV. With our findings CaTiO3 is added to the group of oxides witha 2DEG at their surface. Our study widens the phase space to investigate strontium and barium doped CaTiO3 and the interplay of ferroelectric properties with the 2DEG at oxide surfaces. This could open up new paths to tailor two-dimensional transport properties of these systems towards possible applications. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "Observation of a two-dimensional electron gas at CaTiO3 film surfaces",
volume = "432",
pages = "41-45",
doi = "10.1016/j.apsusc.2017.05.229"
}

Muff, S., Fanciulli, M., Weber, A. P., Pilet, N., Ristić, Z., Wang, Z., Plumb, N. C., Radović, M.,& Dil, J. H.. (2018). Observation of a two-dimensional electron gas at CaTiO3 film surfaces. in Applied Surface Science, 432, 41-45.
https://doi.org/10.1016/j.apsusc.2017.05.229

Muff S, Fanciulli M, Weber AP, Pilet N, Ristić Z, Wang Z, Plumb NC, Radović M, Dil JH. Observation of a two-dimensional electron gas at CaTiO3 film surfaces. in Applied Surface Science. 2018;432:41-45.
doi:10.1016/j.apsusc.2017.05.229 .

Muff, Steffan, Fanciulli, Mauro, Weber, Andrew P., Pilet, Nicolas, Ristić, Zoran, Wang, Zhiming, Plumb, Nicholas C., Radović, Milan, Dil, J. Hugo, "Observation of a two-dimensional electron gas at CaTiO3 film surfaces" in Applied Surface Science, 432 (2018):41-45,
https://doi.org/10.1016/j.apsusc.2017.05.229 . .