George Epurescu - Academia.edu (original) (raw)
Papers by George Epurescu
Nanomaterials, 2022
In this work, thin films of lamellar clays were deposited by laser techniques (matrix assisted pu... more In this work, thin films of lamellar clays were deposited by laser techniques (matrix assisted pulsed laser evaporation (MAPLE) and pulsed laser deposition (PLD)). The focus of this paper is the optimization of deposition parameters for the production of highly oriented crystalline films. The films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Contact angle measurements were employed to identify the wetting properties of the deposited thin films. Hydrophobic to superhydrophilic films can be prepared by using different deposition techniques and deposition parameters. MAPLE led to superhydrophilic films with contact angles in the range 4°–8°, depending on the microstructure and surface roughness at micro and nano scale. The 1064 nm PLD had a high deposition rate and produced a textured film while at λ = 193 nm an extremely thin and amorphous layer was depicted. Oriented kaol...
Journal of the Serbian Chemical Society, 2016
Formulations incorporating benzophenone oligodimethacrylate (BP-DMA) and graphene structures (gra... more Formulations incorporating benzophenone oligodimethacrylate (BP-DMA) and graphene structures (graphene oxide/GO, reduced graphene oxide/RGO) were exposed to UV/vis irradiation or femtosecond laser beam to achieve hybrid composites. All structures were characterized through various methods including 1H NMR and FTIR spectroscopies, optical microscopy, TEM, SEM/EDAX analysis, and DSC/XRD techniques. The photopolymerization of BP-DMA in monomer compositions with and without GO or RGO was investigated by photo-DSC and FTIR methods for determining the polymerization kinetic parameters. The photopolymerization experiments revealed a good photoreactivity of the monomers (degree of conversion: 65-77%) after 1 minute exposure to UV/vis irradiation and the addition of graphene (up to 0.5%), whereas the polymerization rate varied between 0.14 and 0.1 s-1. Moreover, two-photon photopolymerization of the formulations in presence/absence of GO or RGO nanosheets (0.1 wt.%) generated 2D microstructu...
Designed Monomers and Polymers, 2015
Three methacrylated glycomonomers (CMA-1-3) were synthesized, characterized, and photocrosslinked... more Three methacrylated glycomonomers (CMA-1-3) were synthesized, characterized, and photocrosslinked in hydrophilic conetworks. The UV photobehavior of monomers was evaluated through FTIR spectrometry using Irgacure 819/Irgacure 2959 as photoinitiator, and the results showed that Irgacure 2959 is a better photoinitiator, the conversion degree (DC) varying in the range of 69-89.2% and the maximum rate of polymerization (R max p) being ~10 s −1. The addition of poly(ethylene glycol) dimethacrylate (PEG-DMA) or benzophenone macromer (BP-UDMA) as co-monomer improved the R max p and DC (up to 100% after 300 s of irradiation in the latter). Specific analysis (gel fraction, water uptake, morphology) of the photopolymerized networks A1-A3 (CMA-1-3/PEG-DMA) and B1-B3 (CMA-1-3/BP-UDMA) demonstrated that B1-B3 films have interconnected inner pores, with irregular shapes and different sizes. The grid structures created through the two-photon polymerization of B1-B3 formulations in the presence of Irg819 are clearer and have a controlled porosity, of relevance for promising bioapplications.
Superlattices and Microstructures, 2007
The high exciton binding energy and band gap energy of ZnO thin films open the prospect of fabric... more The high exciton binding energy and band gap energy of ZnO thin films open the prospect of fabricating semiconductor lasers in the ultraviolet spectral range. A prerequisite for laser diode fabrication is highly p-doped ZnO which was not reproducibly obtained up to now. Without intentional doping ZnO exhibits n-type conduction. ZnO thin films have been obtained by radio-frequency assisted pulsed
Spectrochimica Acta Part B: Atomic Spectroscopy, 2005
We report a technique that is able to achieve high spatial resolution in the measurement of the t... more We report a technique that is able to achieve high spatial resolution in the measurement of the temporal and spectral emission characteristics of laser-induced expanding plasmas. The plasma is imaged directly onto the slit of an imaging spectrograph coupled to a timegated intensified camera, with the plasma expansion direction being parallel to the slit extension. In this way, a single hybrid detection system is used to acquire the spatial, spectral and temporal characteristics of the laser induced plasma. The parallel acquisition approach of this technique ensures a much better spatial resolution in the expansion direction, reproducibility and data acquisition speed than commonly obtained by sequential measurements at different distances from the target. We have applied this technique to study the laser-induced plasma in LiNbO 3 and Bi 12 Ge 1 O 20 , revealing phenomena not seen in such detail with standard instruments. These include extreme line broadening up to a few nanometers accompanied by self-absorption near the target surface, as well as different ablation and expansion dynamics for the different species ejected. Overall, the high precision and wealth of quantitative information accessible with this technique open up new possibilities for the study of fundamental plasma expansion processes during pulsed laser ablation.
Materials Science in Semiconductor Processing, 2002
ZrO2 thin films have been prepared by laser ablation of Zr or ZrO2 targets in oxygen reactive atm... more ZrO2 thin films have been prepared by laser ablation of Zr or ZrO2 targets in oxygen reactive atmosphere. The influence of the deposition parameters as oxygen pressure and target composition on the structure and morphology of the deposited layers has been studied. Scanning electron microscopy, secondary ion mass spectroscopy and dielectric constant measurements have been performed to characterize the deposited
Materials Science and Engineering: B, 2004
BaTiO3 (Barium titanate, BTO) thin films were grown on Pt coated Si substrates by radiofrequency ... more BaTiO3 (Barium titanate, BTO) thin films were grown on Pt coated Si substrates by radiofrequency discharge assisted pulsed laser deposition (RF-PLD). A standard experimental set-up consisting in a pulsed YAG-Nd laser working at wavelength of 355nm and incident fluence in the range of 2–3J/cm2 and assisted by a radio frequency plasma discharge (power RF of about 50–200W in a O2
Journal of Tissue Engineering and Regenerative Medicine, 2011
Several dermal substitutes for skin grafting are now commercially available, although their perfo... more Several dermal substitutes for skin grafting are now commercially available, although their performance still needs improvement. Most artificial dermises have a lower take rate than autologous grafts and require more time for sufficient vascular ingrowth to overlay the skin graft. Herein we characterize new two-dimensional scaffolds for tissue-engineering applications, which were fabricated by twophoton polymerization (2PP) of ormosils hybrid materials. For the 2PP experiments, a Ti:sapphire laser was used to induce the photopolymerization. In this study we showed that the polymeric structures with controlled architectures produced via 2PP could be used as scaffolds for the in vitro culture and proliferation of human dermal fibroblasts. Fluorescence microscopy revealed that the fibroblasts' orientation was guided by the scaffold geometry, consisting of ormosils lines or grids. This 'dermal equivalent' was investigated for its ability to accommodate epidermal cells. To evaluate this interaction, two experimental approaches were hence used: (a) fibroblast-melanocyte co-cultures; and (b) fibroblast-keratinocyte organotypic cultures. During their growth on ormosil scaffolds, productive interaction of fibroblasts with both epidermal cell types was found. Moreover, this pseudo-dermis was shown to support the growth of keratinocytes for up to 8 days after their seeding.
Journal of Nanoscience and Nanotechnology, 2010
Due to its wide band-gap (ca. 3.4 eV), ZnO is a possible candidate material to be used as transpa... more Due to its wide band-gap (ca. 3.4 eV), ZnO is a possible candidate material to be used as transparent electrode for a new class of photovoltaic (PV) cells. Also, an increased interest for the photovoltaic properties of several organic monomers and polymers (merocyanines, phthalocyanines and porphyrins) was noticed, because of their high optical absorption in the visible region of the spectrum allowing them to be used as potential inexpensive materials for solar cells. Preparation and properties of CuPc (copper phthalocyanine) based photovoltaic cells using ZnO thin films as transparent conductor electrodes are presented in this paper. ZnO layers are grown by pulsed laser deposition, while the organic layers are obtained by thermal evaporation. Structural characterization is performed by electron microscopy. Optical and transport properties of the mutilayered structures are obtained by electrical and spectro-photometric measurements. The influence of the ZnO-polymer interface on the external quantum efficiency (EQE) of the photovoltaic cell is clearly evidenced by our measurements.
Journal of Materials Science: Materials in Electronics, 2008
Journal of Applied Physics, 2008
This work reports on the quantification of self-sputtering and implantation occurring during puls... more This work reports on the quantification of self-sputtering and implantation occurring during pulsed laser deposition of Au as a function of the laser fluence used to ablate the gold target. The experimental approach includes, on one hand, in situ electrical (Langmuir) and optical (two-dimensional imaging) probes for determining, respectively, ion and excited neutral kinetic energy distributions. On the other hand, it includes determination of the density of (i) ions reaching a substrate, and (ii) gold atoms deposited on a substrate as well as of a proportion of atoms that are self-sputtered. The experimental results supported by numerical analysis show that self-sputtering and implantation are both dominated by ions having kinetic energies ≥200 eV. They are a fraction 0.60–0.75 of the species arriving to the substrate for ablation laser fluences 2.7–9.0 J cm−2. Self-sputtering yields in the range 0.60–0.86 are determined for the same fluence range.
IOP Conference Series: Materials Science and Engineering, 2010
... the following: the beam of a pulsed, frequency doubled Nd: YAG laser has been focused through... more ... the following: the beam of a pulsed, frequency doubled Nd: YAG laser has been focused through a quartz lens on an hBN ceramic target ... The observations were carried out with a JEOL 200 CX instrument operating at 200 kV, equipped with a Keen View CCD camera for image ...
Applied Surface Science, 2007
The interest in TiNxOy films has increased recently due to their properties dependence on the N/O... more The interest in TiNxOy films has increased recently due to their properties dependence on the N/O ratio.In this work, we studied comparatively the influence of different flow rate ratios of the reactive gases (O2 and N2) on the properties of the TiNxOy films deposited by two different methods: rf pulsed laser deposition (rf PLD) and reactive pulsed magnetron sputtering (RPM).Film
Applied Surface Science, 2007
Thin films of complex oxides have been deposited by pulsed laser ablation, starting from glass ta... more Thin films of complex oxides have been deposited by pulsed laser ablation, starting from glass targets. Glass oxide targets were prepared by a non-conventional wet method and consisted of a matrix having the composition: Li2O, BaO, Al2O3, La2O3 and P2O5, respectively, non-doped and doped with Nd2O3.The films were deposited on silicon substrates using the fourth harmonic of a Nd:YAG laser
Applied Surface Science, 2005
Zinc oxide thin films were obtained by laser ablation of a Zn target in oxygen reactive atmospher... more Zinc oxide thin films were obtained by laser ablation of a Zn target in oxygen reactive atmosphere, the oxygen being supplied either by a standard gas inlet valve or from a radio-frequency (rf) oxygen plasma. Pt-coated silicon and MgO were used as substrates. The influence of the deposition parameters as laser wavelength (266, 355, 1064 nm), laser fluence (1.5-20 J/cm 2) and oxygen pressure (1-60 Pa) was studied. The influence of the rf plasma beam addition on the morphological proprieties of zinc oxide films was particularly investigated, simultaneously with several configurations of the direction of the ablation plasma, the rf plasma beam and the substrate. The obtained films, with thicknesses in the range of 50 nm to 1 mm have been characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), transmission electron microscopy (TEM).
Applied Surface Science, 2009
Thin films of complex oxides have been obtained by pulsed-laser deposition (PLD) from glass targe... more Thin films of complex oxides have been obtained by pulsed-laser deposition (PLD) from glass targets belonging to the system Li 2 OAl 2 O 3 P 2 O 5 (RE) 2 O 3 , with RE = Nd, Pr, Er. The films were deposited on quartz, silicon and ITO/glass substrates using a F 2 laser (λ = 157 ...
Applied Surface Science, 2013
Binary tin oxide-cerium oxide thin films with ceria concentrations in the range 10-30% have been ... more Binary tin oxide-cerium oxide thin films with ceria concentrations in the range 10-30% have been obtained by pulsed laser deposition technique, with or without additional oxygen RF plasma beam assistance. A good preservation of the Ce/Sn atomic concentration and Ce 3+ content on the film surface of about 30% was obtained for almost all the investigated conditions of substrate temperature and RF powers. The sharp decrease of the electrical resistance in hydrogen environment at temperatures above 300 • C indicates a direct interaction between hydrogen and metal oxides surfaces leading to OH groups formation, as evidenced by XPS measurements. The highest sensitivity (∼40) was attained for the sample with 10% ceria and RF assistance, while the lowest operating temperature (∼250-320 • C) was encountered for that with 30% ceria deposited in the presence of RF discharge.
Nanomaterials, 2022
In this work, thin films of lamellar clays were deposited by laser techniques (matrix assisted pu... more In this work, thin films of lamellar clays were deposited by laser techniques (matrix assisted pulsed laser evaporation (MAPLE) and pulsed laser deposition (PLD)). The focus of this paper is the optimization of deposition parameters for the production of highly oriented crystalline films. The films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Contact angle measurements were employed to identify the wetting properties of the deposited thin films. Hydrophobic to superhydrophilic films can be prepared by using different deposition techniques and deposition parameters. MAPLE led to superhydrophilic films with contact angles in the range 4°–8°, depending on the microstructure and surface roughness at micro and nano scale. The 1064 nm PLD had a high deposition rate and produced a textured film while at λ = 193 nm an extremely thin and amorphous layer was depicted. Oriented kaol...
Journal of the Serbian Chemical Society, 2016
Formulations incorporating benzophenone oligodimethacrylate (BP-DMA) and graphene structures (gra... more Formulations incorporating benzophenone oligodimethacrylate (BP-DMA) and graphene structures (graphene oxide/GO, reduced graphene oxide/RGO) were exposed to UV/vis irradiation or femtosecond laser beam to achieve hybrid composites. All structures were characterized through various methods including 1H NMR and FTIR spectroscopies, optical microscopy, TEM, SEM/EDAX analysis, and DSC/XRD techniques. The photopolymerization of BP-DMA in monomer compositions with and without GO or RGO was investigated by photo-DSC and FTIR methods for determining the polymerization kinetic parameters. The photopolymerization experiments revealed a good photoreactivity of the monomers (degree of conversion: 65-77%) after 1 minute exposure to UV/vis irradiation and the addition of graphene (up to 0.5%), whereas the polymerization rate varied between 0.14 and 0.1 s-1. Moreover, two-photon photopolymerization of the formulations in presence/absence of GO or RGO nanosheets (0.1 wt.%) generated 2D microstructu...
Designed Monomers and Polymers, 2015
Three methacrylated glycomonomers (CMA-1-3) were synthesized, characterized, and photocrosslinked... more Three methacrylated glycomonomers (CMA-1-3) were synthesized, characterized, and photocrosslinked in hydrophilic conetworks. The UV photobehavior of monomers was evaluated through FTIR spectrometry using Irgacure 819/Irgacure 2959 as photoinitiator, and the results showed that Irgacure 2959 is a better photoinitiator, the conversion degree (DC) varying in the range of 69-89.2% and the maximum rate of polymerization (R max p) being ~10 s −1. The addition of poly(ethylene glycol) dimethacrylate (PEG-DMA) or benzophenone macromer (BP-UDMA) as co-monomer improved the R max p and DC (up to 100% after 300 s of irradiation in the latter). Specific analysis (gel fraction, water uptake, morphology) of the photopolymerized networks A1-A3 (CMA-1-3/PEG-DMA) and B1-B3 (CMA-1-3/BP-UDMA) demonstrated that B1-B3 films have interconnected inner pores, with irregular shapes and different sizes. The grid structures created through the two-photon polymerization of B1-B3 formulations in the presence of Irg819 are clearer and have a controlled porosity, of relevance for promising bioapplications.
Superlattices and Microstructures, 2007
The high exciton binding energy and band gap energy of ZnO thin films open the prospect of fabric... more The high exciton binding energy and band gap energy of ZnO thin films open the prospect of fabricating semiconductor lasers in the ultraviolet spectral range. A prerequisite for laser diode fabrication is highly p-doped ZnO which was not reproducibly obtained up to now. Without intentional doping ZnO exhibits n-type conduction. ZnO thin films have been obtained by radio-frequency assisted pulsed
Spectrochimica Acta Part B: Atomic Spectroscopy, 2005
We report a technique that is able to achieve high spatial resolution in the measurement of the t... more We report a technique that is able to achieve high spatial resolution in the measurement of the temporal and spectral emission characteristics of laser-induced expanding plasmas. The plasma is imaged directly onto the slit of an imaging spectrograph coupled to a timegated intensified camera, with the plasma expansion direction being parallel to the slit extension. In this way, a single hybrid detection system is used to acquire the spatial, spectral and temporal characteristics of the laser induced plasma. The parallel acquisition approach of this technique ensures a much better spatial resolution in the expansion direction, reproducibility and data acquisition speed than commonly obtained by sequential measurements at different distances from the target. We have applied this technique to study the laser-induced plasma in LiNbO 3 and Bi 12 Ge 1 O 20 , revealing phenomena not seen in such detail with standard instruments. These include extreme line broadening up to a few nanometers accompanied by self-absorption near the target surface, as well as different ablation and expansion dynamics for the different species ejected. Overall, the high precision and wealth of quantitative information accessible with this technique open up new possibilities for the study of fundamental plasma expansion processes during pulsed laser ablation.
Materials Science in Semiconductor Processing, 2002
ZrO2 thin films have been prepared by laser ablation of Zr or ZrO2 targets in oxygen reactive atm... more ZrO2 thin films have been prepared by laser ablation of Zr or ZrO2 targets in oxygen reactive atmosphere. The influence of the deposition parameters as oxygen pressure and target composition on the structure and morphology of the deposited layers has been studied. Scanning electron microscopy, secondary ion mass spectroscopy and dielectric constant measurements have been performed to characterize the deposited
Materials Science and Engineering: B, 2004
BaTiO3 (Barium titanate, BTO) thin films were grown on Pt coated Si substrates by radiofrequency ... more BaTiO3 (Barium titanate, BTO) thin films were grown on Pt coated Si substrates by radiofrequency discharge assisted pulsed laser deposition (RF-PLD). A standard experimental set-up consisting in a pulsed YAG-Nd laser working at wavelength of 355nm and incident fluence in the range of 2–3J/cm2 and assisted by a radio frequency plasma discharge (power RF of about 50–200W in a O2
Journal of Tissue Engineering and Regenerative Medicine, 2011
Several dermal substitutes for skin grafting are now commercially available, although their perfo... more Several dermal substitutes for skin grafting are now commercially available, although their performance still needs improvement. Most artificial dermises have a lower take rate than autologous grafts and require more time for sufficient vascular ingrowth to overlay the skin graft. Herein we characterize new two-dimensional scaffolds for tissue-engineering applications, which were fabricated by twophoton polymerization (2PP) of ormosils hybrid materials. For the 2PP experiments, a Ti:sapphire laser was used to induce the photopolymerization. In this study we showed that the polymeric structures with controlled architectures produced via 2PP could be used as scaffolds for the in vitro culture and proliferation of human dermal fibroblasts. Fluorescence microscopy revealed that the fibroblasts' orientation was guided by the scaffold geometry, consisting of ormosils lines or grids. This 'dermal equivalent' was investigated for its ability to accommodate epidermal cells. To evaluate this interaction, two experimental approaches were hence used: (a) fibroblast-melanocyte co-cultures; and (b) fibroblast-keratinocyte organotypic cultures. During their growth on ormosil scaffolds, productive interaction of fibroblasts with both epidermal cell types was found. Moreover, this pseudo-dermis was shown to support the growth of keratinocytes for up to 8 days after their seeding.
Journal of Nanoscience and Nanotechnology, 2010
Due to its wide band-gap (ca. 3.4 eV), ZnO is a possible candidate material to be used as transpa... more Due to its wide band-gap (ca. 3.4 eV), ZnO is a possible candidate material to be used as transparent electrode for a new class of photovoltaic (PV) cells. Also, an increased interest for the photovoltaic properties of several organic monomers and polymers (merocyanines, phthalocyanines and porphyrins) was noticed, because of their high optical absorption in the visible region of the spectrum allowing them to be used as potential inexpensive materials for solar cells. Preparation and properties of CuPc (copper phthalocyanine) based photovoltaic cells using ZnO thin films as transparent conductor electrodes are presented in this paper. ZnO layers are grown by pulsed laser deposition, while the organic layers are obtained by thermal evaporation. Structural characterization is performed by electron microscopy. Optical and transport properties of the mutilayered structures are obtained by electrical and spectro-photometric measurements. The influence of the ZnO-polymer interface on the external quantum efficiency (EQE) of the photovoltaic cell is clearly evidenced by our measurements.
Journal of Materials Science: Materials in Electronics, 2008
Journal of Applied Physics, 2008
This work reports on the quantification of self-sputtering and implantation occurring during puls... more This work reports on the quantification of self-sputtering and implantation occurring during pulsed laser deposition of Au as a function of the laser fluence used to ablate the gold target. The experimental approach includes, on one hand, in situ electrical (Langmuir) and optical (two-dimensional imaging) probes for determining, respectively, ion and excited neutral kinetic energy distributions. On the other hand, it includes determination of the density of (i) ions reaching a substrate, and (ii) gold atoms deposited on a substrate as well as of a proportion of atoms that are self-sputtered. The experimental results supported by numerical analysis show that self-sputtering and implantation are both dominated by ions having kinetic energies ≥200 eV. They are a fraction 0.60–0.75 of the species arriving to the substrate for ablation laser fluences 2.7–9.0 J cm−2. Self-sputtering yields in the range 0.60–0.86 are determined for the same fluence range.
IOP Conference Series: Materials Science and Engineering, 2010
... the following: the beam of a pulsed, frequency doubled Nd: YAG laser has been focused through... more ... the following: the beam of a pulsed, frequency doubled Nd: YAG laser has been focused through a quartz lens on an hBN ceramic target ... The observations were carried out with a JEOL 200 CX instrument operating at 200 kV, equipped with a Keen View CCD camera for image ...
Applied Surface Science, 2007
The interest in TiNxOy films has increased recently due to their properties dependence on the N/O... more The interest in TiNxOy films has increased recently due to their properties dependence on the N/O ratio.In this work, we studied comparatively the influence of different flow rate ratios of the reactive gases (O2 and N2) on the properties of the TiNxOy films deposited by two different methods: rf pulsed laser deposition (rf PLD) and reactive pulsed magnetron sputtering (RPM).Film
Applied Surface Science, 2007
Thin films of complex oxides have been deposited by pulsed laser ablation, starting from glass ta... more Thin films of complex oxides have been deposited by pulsed laser ablation, starting from glass targets. Glass oxide targets were prepared by a non-conventional wet method and consisted of a matrix having the composition: Li2O, BaO, Al2O3, La2O3 and P2O5, respectively, non-doped and doped with Nd2O3.The films were deposited on silicon substrates using the fourth harmonic of a Nd:YAG laser
Applied Surface Science, 2005
Zinc oxide thin films were obtained by laser ablation of a Zn target in oxygen reactive atmospher... more Zinc oxide thin films were obtained by laser ablation of a Zn target in oxygen reactive atmosphere, the oxygen being supplied either by a standard gas inlet valve or from a radio-frequency (rf) oxygen plasma. Pt-coated silicon and MgO were used as substrates. The influence of the deposition parameters as laser wavelength (266, 355, 1064 nm), laser fluence (1.5-20 J/cm 2) and oxygen pressure (1-60 Pa) was studied. The influence of the rf plasma beam addition on the morphological proprieties of zinc oxide films was particularly investigated, simultaneously with several configurations of the direction of the ablation plasma, the rf plasma beam and the substrate. The obtained films, with thicknesses in the range of 50 nm to 1 mm have been characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), transmission electron microscopy (TEM).
Applied Surface Science, 2009
Thin films of complex oxides have been obtained by pulsed-laser deposition (PLD) from glass targe... more Thin films of complex oxides have been obtained by pulsed-laser deposition (PLD) from glass targets belonging to the system Li 2 OAl 2 O 3 P 2 O 5 (RE) 2 O 3 , with RE = Nd, Pr, Er. The films were deposited on quartz, silicon and ITO/glass substrates using a F 2 laser (λ = 157 ...
Applied Surface Science, 2013
Binary tin oxide-cerium oxide thin films with ceria concentrations in the range 10-30% have been ... more Binary tin oxide-cerium oxide thin films with ceria concentrations in the range 10-30% have been obtained by pulsed laser deposition technique, with or without additional oxygen RF plasma beam assistance. A good preservation of the Ce/Sn atomic concentration and Ce 3+ content on the film surface of about 30% was obtained for almost all the investigated conditions of substrate temperature and RF powers. The sharp decrease of the electrical resistance in hydrogen environment at temperatures above 300 • C indicates a direct interaction between hydrogen and metal oxides surfaces leading to OH groups formation, as evidenced by XPS measurements. The highest sensitivity (∼40) was attained for the sample with 10% ceria and RF assistance, while the lowest operating temperature (∼250-320 • C) was encountered for that with 30% ceria deposited in the presence of RF discharge.