Cristina Chirila

Dr. Cristina Chirila

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 January 2014 in ACS Applied Materials & Interfaces
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Journal Article
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Ioana PINTILIEIoana PINTILIE
Ioana PINTILIE
Cristian-Mihail TeodorescuCristian-Mihail Teodorescu
Cristian-Mihail Teodorescu
CGCorneliu Ghica
Corneliu Ghica
CCCristina Chirila
Cristina Chirila
ABAndra-Georgia Boni
Andra-Georgia Boni
Lucian PintilieLucian Pintilie
Lucian Pintilie

5 March 2014 in Physica Status Solidi (RRL) – Rapid Research Letters
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Journal Article
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SLShunyi Li
Shunyi Li
FCFeng Chen
Feng Chen
RSRobert Schafranek
Robert Schafranek
TBThorsten J. M. Bayer
Thorsten J. M. Bayer
KRKarsten Rachut
Karsten Rachut
AKAndreas Klein
Andreas Klein

8 October 2015 in Scientific Reports
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Journal Article
Open access
Lucian PintilieLucian Pintilie
Lucian Pintilie
CGCorneliu Ghica
Corneliu Ghica
Cristian-Mihail TeodorescuCristian-Mihail Teodorescu
Cristian-Mihail Teodorescu
Ioana PINTILIEIoana PINTILIE
Ioana PINTILIE
CCCristina Chirila
Cristina Chirila
Daniela GhicaDaniela Ghica
Daniela Ghica
The compensation of the depolarization field in ferroelectric layers requires the presence of a suitable amount of charges able to follow any variation of the ferroelectric polarization. These can be free carriers or charged defects located in the ferroelectric material or free carriers coming from the electrodes. Here we show that a self-doping phenomenon occurs in epitaxial, tetragonal ferroelectric films of Pb(Zr0.2Ti0.8)O3, consisting in generation of point defects (vacancies) acting as donors/acceptors. These are introducing free carriers that partly compensate the depolarization field occurring in the film. It is found that the concentration of the free carriers introduced by self-doping increases with decreasing the thickness of the ferroelectric layer, reaching values of the order of 1026 m−3for 10 nm thick films. One the other hand, microscopic investigations show that, for thicknesses higher than 50 nm, the 2O/(Ti+Zr+Pb) atomic ratio increases with the thickness of the layers. These results suggest that the ratio between the oxygen and cation vacancies varies with the thickness of the layer in such a way that the net free carrier density is sufficient to efficiently compensate the depolarization field and to preserve the outward direction of the polarization.

17 July 2013 in Physical Review B
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SLShunyi Li
Shunyi Li
JMJan Morasch
Jan Morasch
AKAndreas Klein
Andreas Klein
CCCristina Chirila
Cristina Chirila
Lucian PintilieLucian Pintilie
Lucian Pintilie
KAKarsten Albe
Karsten Albe
The formation of an interface between Bi${}_{2}$O${}_{3}$, Fe${}_{2}$O${}_{3}$, BiFeO${}_{3}$, Bi${}_{0.5}$Na${}_{0.5}$TiO${}_{3}$, and the high work function metallic RuO${}_{2}$ is studied using photoelectron spectroscopy with in situ RuO${}_{2}$ deposition. Schottky barrier heights are derived and the valence band maximum energies of the studied materials are aligned with respect to each other as well as to other functional oxides like SrTiO${}_{3}$ and PbTiO${}_{3}$. The energy band alignment follows systematic trends compared to a large number of oxides, and can be understood in terms of the contribution of Fe $3d$ and Bi $6s/6p$ (lone pair) orbitals to electronic states near the valence band maximum. The results indicate that the valence band maxima are largely determined by the local environment of the cations, which allows to estimate valence band maximum energies of oxides with multiple cations from those of their parent binary compounds. The high valence band maximum of BiFeO${}_{3}$ is consistent with reported $p$-type conduction of acceptor doped material, while the high conduction band minimum makes $n$-type conduction unlikely.

1 May 2013 in Applied Surface Science
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NANicoleta G. Apostol
Nicoleta G. Apostol
LSLaura E. Stoflea
Laura E. Stoflea
GLGeorge A. Lungu
George A. Lungu
CCCristina Chirila
Cristina Chirila
LTLucian Trupina
Lucian Trupina
Cristian-Mihail TeodorescuCristian-Mihail Teodorescu
Cristian-Mihail Teodorescu

28 December 2015 in Physical Review B
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Journal Article
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DPDana G. Popescu
Dana G. Popescu
NBNicholas Barrett
Nicholas Barrett
CCCristina Chirila
Cristina Chirila
IPIuliana Pasuk
Iuliana Pasuk
MHMarius A. Husanu
Marius A. Husanu
The effects of the bonding mechanism and band alignment in a ferroelectric (FE) BaTiO3/ferromagnetic La0.6Sr0.4MnO3 heterostructure are studied using x-ray photoelectron spectroscopy and first-principles calculations. The band lineup at the interface is determined by a combination of band bending and polarization-induced modification of core-hole screening. A Schottky barrier height for electrons of 1.22±0.17 eV is obtained in the case of downwards FE polarization of the top layer. The symmetry of the bonding states is emphasized by integrating the local density of states ±0.2 eV around the Fermi level, and strong dependence on the FE polarization is found: upwards, polarization stabilizes Ti t2g(xy) orbitals, while downwards, polarization favors Ti t2g(yz) symmetry. It is predicted that the abrupt (La,Sr)|TiO2 interface is magnetoelectrically active, leading to a A-type antiferromagnetic coupling of the first TiO2 interface layer with the underlying manganite layer through a superexchange mechanism.