TY  - JOUR
AU  - Cherneva, Sabina
AU  - Iankov, ROumen
AU  - Radić, Nenad
AU  - Grbić, Boško
AU  - Datcheva, Maria
AU  - Stoychev, Dimitar
PY  - 2017
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2184
AB  - The aim of the present work is to determine the indentation hardness (HIT) and indentation modulus (EIT) of pure TiO2 and WO3 thin films, as well as thin films composed of different TiO2 and WO3 proportions and deposited by spray pyrolysis on a stainless-steel (OC 404) substrate. Since the HIT and EIT of the films are properties expected to depend on the phase-chemical composition, morphology, structure and their changes when increasing the WO3 content in the TiO2-WO3 composite film, the correlation between the mechanical and structural properties is also addressed. The obtained results show that HIT and EIT strongly depend on the concentration of the co-deposited WO3. The determined values of HIT and EIT noticeably decrease (in comparison with HIT and EIT of the pure (100 %) TiO2 layer) when very low concentrations of WO3 (up to 2.5 % of W) are co-deposited. At higher concentrations of the co-deposited WO3 (more than 2.5 % of W), the HIT and EIT values increase almost linearly with an increase of the WO3 in the precursor. The observed non-proportional behavior of HIT and EIT is associated with specific changes of the structure and a development of defects in the deposited TiO2-WO3 composite phase, as well as with the increase in the amount of the formed separate WO3 phase (with increasing of WO3 (H2W3O12) in the working solution) surrounded by solitary TiO2 particles.
PB  - Institute of Metals and Technology
T2  - Materiali in Tehnologije
T1  - Nano-indentation investigations of the mechanical properties of thin tio2, wo3 and their composites layers, deposited by spray pyrolysis
VL  - 51
IS  - 1
SP  - 75
EP  - 83
DO  - 10.17222/mit.2015.216
ER  - 

@article{
author = "Cherneva, Sabina and Iankov, ROumen and Radić, Nenad and Grbić, Boško and Datcheva, Maria and Stoychev, Dimitar",
year = "2017",
abstract = "The aim of the present work is to determine the indentation hardness (HIT) and indentation modulus (EIT) of pure TiO2 and WO3 thin films, as well as thin films composed of different TiO2 and WO3 proportions and deposited by spray pyrolysis on a stainless-steel (OC 404) substrate. Since the HIT and EIT of the films are properties expected to depend on the phase-chemical composition, morphology, structure and their changes when increasing the WO3 content in the TiO2-WO3 composite film, the correlation between the mechanical and structural properties is also addressed. The obtained results show that HIT and EIT strongly depend on the concentration of the co-deposited WO3. The determined values of HIT and EIT noticeably decrease (in comparison with HIT and EIT of the pure (100 %) TiO2 layer) when very low concentrations of WO3 (up to 2.5 % of W) are co-deposited. At higher concentrations of the co-deposited WO3 (more than 2.5 % of W), the HIT and EIT values increase almost linearly with an increase of the WO3 in the precursor. The observed non-proportional behavior of HIT and EIT is associated with specific changes of the structure and a development of defects in the deposited TiO2-WO3 composite phase, as well as with the increase in the amount of the formed separate WO3 phase (with increasing of WO3 (H2W3O12) in the working solution) surrounded by solitary TiO2 particles.",
publisher = "Institute of Metals and Technology",
journal = "Materiali in Tehnologije",
title = "Nano-indentation investigations of the mechanical properties of thin tio2, wo3 and their composites layers, deposited by spray pyrolysis",
volume = "51",
number = "1",
pages = "75-83",
doi = "10.17222/mit.2015.216"
}

Cherneva, S., Iankov, R., Radić, N., Grbić, B., Datcheva, M.,& Stoychev, D.. (2017). Nano-indentation investigations of the mechanical properties of thin tio2, wo3 and their composites layers, deposited by spray pyrolysis. in Materiali in Tehnologije
Institute of Metals and Technology., 51(1), 75-83.
https://doi.org/10.17222/mit.2015.216

Cherneva S, Iankov R, Radić N, Grbić B, Datcheva M, Stoychev D. Nano-indentation investigations of the mechanical properties of thin tio2, wo3 and their composites layers, deposited by spray pyrolysis. in Materiali in Tehnologije. 2017;51(1):75-83.
doi:10.17222/mit.2015.216 .

Cherneva, Sabina, Iankov, ROumen, Radić, Nenad, Grbić, Boško, Datcheva, Maria, Stoychev, Dimitar, "Nano-indentation investigations of the mechanical properties of thin tio2, wo3 and their composites layers, deposited by spray pyrolysis" in Materiali in Tehnologije, 51, no. 1 (2017):75-83,
https://doi.org/10.17222/mit.2015.216 . .

TY  - JOUR
AU  - Cherneva, Sabina
AU  - Iankov, Roumen
AU  - Radić, Nenad
AU  - Grbić, Boško
AU  - Stoychev, Dimitar
PY  - 2014
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1521
AB  - Thin ZrO2, ZrO2-Y2O3, Al2O3 and TiO2 films were deposited by spray pyrolysis method on stainless steel DC 404 substrate with thickness 50 mu m. The thicknesses of obtained films varied from 0.50 to 0.64 mu m. The surface morphology and structure of the films were characterized by scanning electron microscopy in secondary electron imaging mode. The X-ray diffraction measurements for determination of the lattice parameters, the average crystallite size and the sample strain were performed. Mechanical properties of investigated films and substrate were investigated by nanoindentation experiments, using Nano Indenter G200 (Agilent Technologies). As a result of nanoindentation experiments, load-displacement curves were obtained and two mechanical characteristics of the substrate and investigated films - indentation hardness (H-IT) and indentation modulus (E-IT) - were calculated using Oliver & Pharr approximation method. Dependence of indentation modulus and indentation hardness on depth of indentation was investigated as well. 2013 Elsevier B.V. All rights reserved.
PB  - Elsevier
T2  - Materials Science and Engineering B-Advanced Functional Solid-State Materials
T1  - Nanoindentation investigation of mechanical properties of ZrO2, ZrO2-Y2O3, Al2O3 and TiO2 thin films deposited on stainless steel OC 4O4 substrate by spray pyrolysis
VL  - 183
SP  - 12
EP  - 16
DO  - 10.1016/j.mseb.2013.12.006
ER  - 

@article{
author = "Cherneva, Sabina and Iankov, Roumen and Radić, Nenad and Grbić, Boško and Stoychev, Dimitar",
year = "2014",
abstract = "Thin ZrO2, ZrO2-Y2O3, Al2O3 and TiO2 films were deposited by spray pyrolysis method on stainless steel DC 404 substrate with thickness 50 mu m. The thicknesses of obtained films varied from 0.50 to 0.64 mu m. The surface morphology and structure of the films were characterized by scanning electron microscopy in secondary electron imaging mode. The X-ray diffraction measurements for determination of the lattice parameters, the average crystallite size and the sample strain were performed. Mechanical properties of investigated films and substrate were investigated by nanoindentation experiments, using Nano Indenter G200 (Agilent Technologies). As a result of nanoindentation experiments, load-displacement curves were obtained and two mechanical characteristics of the substrate and investigated films - indentation hardness (H-IT) and indentation modulus (E-IT) - were calculated using Oliver & Pharr approximation method. Dependence of indentation modulus and indentation hardness on depth of indentation was investigated as well. 2013 Elsevier B.V. All rights reserved.",
publisher = "Elsevier",
journal = "Materials Science and Engineering B-Advanced Functional Solid-State Materials",
title = "Nanoindentation investigation of mechanical properties of ZrO2, ZrO2-Y2O3, Al2O3 and TiO2 thin films deposited on stainless steel OC 4O4 substrate by spray pyrolysis",
volume = "183",
pages = "12-16",
doi = "10.1016/j.mseb.2013.12.006"
}

Cherneva, S., Iankov, R., Radić, N., Grbić, B.,& Stoychev, D.. (2014). Nanoindentation investigation of mechanical properties of ZrO2, ZrO2-Y2O3, Al2O3 and TiO2 thin films deposited on stainless steel OC 4O4 substrate by spray pyrolysis. in Materials Science and Engineering B-Advanced Functional Solid-State Materials
Elsevier., 183, 12-16.
https://doi.org/10.1016/j.mseb.2013.12.006

Cherneva S, Iankov R, Radić N, Grbić B, Stoychev D. Nanoindentation investigation of mechanical properties of ZrO2, ZrO2-Y2O3, Al2O3 and TiO2 thin films deposited on stainless steel OC 4O4 substrate by spray pyrolysis. in Materials Science and Engineering B-Advanced Functional Solid-State Materials. 2014;183:12-16.
doi:10.1016/j.mseb.2013.12.006 .

Cherneva, Sabina, Iankov, Roumen, Radić, Nenad, Grbić, Boško, Stoychev, Dimitar, "Nanoindentation investigation of mechanical properties of ZrO2, ZrO2-Y2O3, Al2O3 and TiO2 thin films deposited on stainless steel OC 4O4 substrate by spray pyrolysis" in Materials Science and Engineering B-Advanced Functional Solid-State Materials, 183 (2014):12-16,
https://doi.org/10.1016/j.mseb.2013.12.006 . .

TY  - JOUR
AU  - Radić, Nenad
AU  - Grbić, Boško
AU  - Rožić, Ljiljana
AU  - Novaković, Tatjana
AU  - Petrović, Srđan
AU  - Stoychev, Dimitar
AU  - Stefanov, Plamen
PY  - 2011
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/846
AB  - Alumina coatings were obtained by deposition of boehmite sol, with added polyvinyl alcohol or polyethylene glycol, on stainless steel foil by spray pyrolysis method. Characterizations of coatings were performed by SEM, XRD, XPS, AFM and S(BET) analysis. Alumina coating prepared with polyethylene glycol has improved resistance to surface area loss than coating obtained with polyvinyl alcohol. At elevated temperatures polyethylene glycol has preserved the morphology of alumina coating and prevents the diffusion of Fe from stainless steel substrate. Porous, foam-like aluminium oxide coating, consisted of accidentally distributed rings of alumina, was created from both additives. Such coating morphology, with a hierarchical porosity, has application in numerous catalytic processes.
PB  - Elsevier
T2  - Journal of Non-Crystalline Solids
T1  - Effects of organic additives on alumina coatings on stainless steel obtained by spray pyrolysis
VL  - 357
IS  - 21
SP  - 3592
EP  - 3597
DO  - 10.1016/j.jnoncrysol.2011.07.006
ER  - 

@article{
author = "Radić, Nenad and Grbić, Boško and Rožić, Ljiljana and Novaković, Tatjana and Petrović, Srđan and Stoychev, Dimitar and Stefanov, Plamen",
year = "2011",
abstract = "Alumina coatings were obtained by deposition of boehmite sol, with added polyvinyl alcohol or polyethylene glycol, on stainless steel foil by spray pyrolysis method. Characterizations of coatings were performed by SEM, XRD, XPS, AFM and S(BET) analysis. Alumina coating prepared with polyethylene glycol has improved resistance to surface area loss than coating obtained with polyvinyl alcohol. At elevated temperatures polyethylene glycol has preserved the morphology of alumina coating and prevents the diffusion of Fe from stainless steel substrate. Porous, foam-like aluminium oxide coating, consisted of accidentally distributed rings of alumina, was created from both additives. Such coating morphology, with a hierarchical porosity, has application in numerous catalytic processes.",
publisher = "Elsevier",
journal = "Journal of Non-Crystalline Solids",
title = "Effects of organic additives on alumina coatings on stainless steel obtained by spray pyrolysis",
volume = "357",
number = "21",
pages = "3592-3597",
doi = "10.1016/j.jnoncrysol.2011.07.006"
}

Radić, N., Grbić, B., Rožić, L., Novaković, T., Petrović, S., Stoychev, D.,& Stefanov, P.. (2011). Effects of organic additives on alumina coatings on stainless steel obtained by spray pyrolysis. in Journal of Non-Crystalline Solids
Elsevier., 357(21), 3592-3597.
https://doi.org/10.1016/j.jnoncrysol.2011.07.006

Radić N, Grbić B, Rožić L, Novaković T, Petrović S, Stoychev D, Stefanov P. Effects of organic additives on alumina coatings on stainless steel obtained by spray pyrolysis. in Journal of Non-Crystalline Solids. 2011;357(21):3592-3597.
doi:10.1016/j.jnoncrysol.2011.07.006 .

Radić, Nenad, Grbić, Boško, Rožić, Ljiljana, Novaković, Tatjana, Petrović, Srđan, Stoychev, Dimitar, Stefanov, Plamen, "Effects of organic additives on alumina coatings on stainless steel obtained by spray pyrolysis" in Journal of Non-Crystalline Solids, 357, no. 21 (2011):3592-3597,
https://doi.org/10.1016/j.jnoncrysol.2011.07.006 . .

TY  - JOUR
AU  - Anic, Mirjana
AU  - Radić, Nenad
AU  - Grbić, Boško
AU  - Dondur, Vera
AU  - Damjanović, Ljiljana
AU  - Stoychev, Dimitar
AU  - Stefanov, Plamen
PY  - 2011
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/865
AB  - The deep oxidation of n-hexane was studied over Pt catalysts with small and large Pt crystallites, promoted by MnOx. The Mn was deposited on the Pt/Al2O3 by deposition-precipitation method using two alkalis, ammonia and dimethylamine. The strength of the base influenced morphology and performances of Mn-Pt catalysts. Ammonia formed mostly spherical structure of manganese oxide, while dimethylamine created fibrous needle-like shape of MnOx, typical for cryptomelane phase of manganese oxide. This was confirmed by XPS results that show an oxidation state of Mn close to that for cryptomelane. The Pt-Mn catalysts were more active than catalysts containing Pt only. Promoting effect of MnOx is more pronounced for larger Pt crystallites. Among Pt-Mn samples, catalysts synthesized with dimethylamine exhibited the highest activities. Mobility and reactivity of oxygen from Pt-O-Mn sites associated with cryptomelane phase may be responsible for increased activity.
PB  - Elsevier
T2  - Applied Catalysis B-Environmental
T1  - Catalytic activity of Pt catalysts promoted by MnOx for n-hexane oxidation
VL  - 107
IS  - 3-4
SP  - 327
EP  - 332
DO  - 10.1016/j.apcatb.2011.07.032
ER  - 

@article{
author = "Anic, Mirjana and Radić, Nenad and Grbić, Boško and Dondur, Vera and Damjanović, Ljiljana and Stoychev, Dimitar and Stefanov, Plamen",
year = "2011",
abstract = "The deep oxidation of n-hexane was studied over Pt catalysts with small and large Pt crystallites, promoted by MnOx. The Mn was deposited on the Pt/Al2O3 by deposition-precipitation method using two alkalis, ammonia and dimethylamine. The strength of the base influenced morphology and performances of Mn-Pt catalysts. Ammonia formed mostly spherical structure of manganese oxide, while dimethylamine created fibrous needle-like shape of MnOx, typical for cryptomelane phase of manganese oxide. This was confirmed by XPS results that show an oxidation state of Mn close to that for cryptomelane. The Pt-Mn catalysts were more active than catalysts containing Pt only. Promoting effect of MnOx is more pronounced for larger Pt crystallites. Among Pt-Mn samples, catalysts synthesized with dimethylamine exhibited the highest activities. Mobility and reactivity of oxygen from Pt-O-Mn sites associated with cryptomelane phase may be responsible for increased activity.",
publisher = "Elsevier",
journal = "Applied Catalysis B-Environmental",
title = "Catalytic activity of Pt catalysts promoted by MnOx for n-hexane oxidation",
volume = "107",
number = "3-4",
pages = "327-332",
doi = "10.1016/j.apcatb.2011.07.032"
}

Anic, M., Radić, N., Grbić, B., Dondur, V., Damjanović, L., Stoychev, D.,& Stefanov, P.. (2011). Catalytic activity of Pt catalysts promoted by MnOx for n-hexane oxidation. in Applied Catalysis B-Environmental
Elsevier., 107(3-4), 327-332.
https://doi.org/10.1016/j.apcatb.2011.07.032

Anic M, Radić N, Grbić B, Dondur V, Damjanović L, Stoychev D, Stefanov P. Catalytic activity of Pt catalysts promoted by MnOx for n-hexane oxidation. in Applied Catalysis B-Environmental. 2011;107(3-4):327-332.
doi:10.1016/j.apcatb.2011.07.032 .

Anic, Mirjana, Radić, Nenad, Grbić, Boško, Dondur, Vera, Damjanović, Ljiljana, Stoychev, Dimitar, Stefanov, Plamen, "Catalytic activity of Pt catalysts promoted by MnOx for n-hexane oxidation" in Applied Catalysis B-Environmental, 107, no. 3-4 (2011):327-332,
https://doi.org/10.1016/j.apcatb.2011.07.032 . .

TY  - JOUR
AU  - Novaković, Tatjana
AU  - Radić, Nenad
AU  - Grbić, Boško
AU  - Dondur, Vera
AU  - Mitrić, Miodrag
AU  - Randjelović, Danijela
AU  - Stoychev, Dimitar
AU  - Stefanov, Plamen
PY  - 2008
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/388
AB  - Active porous alumina coatings were obtained by deposition of boehmite sol on stainless steel (SS) substrate by spray pyrolysis method. The temperature and the doping of polyethylene glycol (PEG) and La3+ in the boehmite sol effects on the textural and structural properties and surface morphology of alumina coatings on stainless steel samples are presented. It was found that the addition of polyethylene glycol combined with La3+ to the boehmite sol before spraying improves the thermal stability of porous alumina coatings. X-ray diffraction patterns of a doped sample, even after 5 h at 1000 degrees C, point out to the presence only of delta-Al2O3, with a S-BET of 74 m(2)/g. XPS data and SEM photographs of coated samples show that alumina were well deposited on the metallic supports. The absence of any lanthanum compounds indicates very well homogeneous dispersion of La3+-ions on the surface of alumina crystallites. AFM images show sphere like alumina grains and agglomerates with surface roughness from 60 to 180 nm, depending on temperature and doping. Surface roughness of doped alumina samples was higher than that of non-doped. It was pointed out that spray pyrolysis method enables preparation of alumina layers with relatively high specific surface area, suitable for applications as catalysts supports.
PB  - Elsevier
T2  - Applied Surface Science
T1  - The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis
VL  - 255
IS  - 5
SP  - 3049
EP  - 3055
DO  - 10.1016/j.apsusc.2008.08.074
ER  - 

@article{
author = "Novaković, Tatjana and Radić, Nenad and Grbić, Boško and Dondur, Vera and Mitrić, Miodrag and Randjelović, Danijela and Stoychev, Dimitar and Stefanov, Plamen",
year = "2008",
abstract = "Active porous alumina coatings were obtained by deposition of boehmite sol on stainless steel (SS) substrate by spray pyrolysis method. The temperature and the doping of polyethylene glycol (PEG) and La3+ in the boehmite sol effects on the textural and structural properties and surface morphology of alumina coatings on stainless steel samples are presented. It was found that the addition of polyethylene glycol combined with La3+ to the boehmite sol before spraying improves the thermal stability of porous alumina coatings. X-ray diffraction patterns of a doped sample, even after 5 h at 1000 degrees C, point out to the presence only of delta-Al2O3, with a S-BET of 74 m(2)/g. XPS data and SEM photographs of coated samples show that alumina were well deposited on the metallic supports. The absence of any lanthanum compounds indicates very well homogeneous dispersion of La3+-ions on the surface of alumina crystallites. AFM images show sphere like alumina grains and agglomerates with surface roughness from 60 to 180 nm, depending on temperature and doping. Surface roughness of doped alumina samples was higher than that of non-doped. It was pointed out that spray pyrolysis method enables preparation of alumina layers with relatively high specific surface area, suitable for applications as catalysts supports.",
publisher = "Elsevier",
journal = "Applied Surface Science",
title = "The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis",
volume = "255",
number = "5",
pages = "3049-3055",
doi = "10.1016/j.apsusc.2008.08.074"
}

Novaković, T., Radić, N., Grbić, B., Dondur, V., Mitrić, M., Randjelović, D., Stoychev, D.,& Stefanov, P.. (2008). The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis. in Applied Surface Science
Elsevier., 255(5), 3049-3055.
https://doi.org/10.1016/j.apsusc.2008.08.074

Novaković T, Radić N, Grbić B, Dondur V, Mitrić M, Randjelović D, Stoychev D, Stefanov P. The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis. in Applied Surface Science. 2008;255(5):3049-3055.
doi:10.1016/j.apsusc.2008.08.074 .

Novaković, Tatjana, Radić, Nenad, Grbić, Boško, Dondur, Vera, Mitrić, Miodrag, Randjelović, Danijela, Stoychev, Dimitar, Stefanov, Plamen, "The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis" in Applied Surface Science, 255, no. 5 (2008):3049-3055,
https://doi.org/10.1016/j.apsusc.2008.08.074 . .