The nonmonotonic dependence of the intensities of vibrational lines in the Raman scattering of TiO2 nanofilms, including Ag and Au nanoparticles, from the irradiation dose D by Ti+ (140 keV) ions was estab-lished. The increase of the intensity in 1.3-1.5 times for TiO2 films at D  1012 - 1013 ions/cm2 related with improved of films structure at low doses. The enhancement of low-frequency electronic bands with dose in-creasing was study. It was shown that the effect of plasmon is not a major and the vibrational-electronic interaction plays the main function.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3529

Busko, T.O.

Kornienko, N.E.

Kulish, N.P.

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  
NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 2 No 1, 01PCSI25(2pp) (2013) 
 
 
2304-1862/2013/2(1)01PCSI25(2) 01PCSI25-1  2013 Sumy State University 
Variation of the Vibration and Electronic States at Ion Irradiation 
of TiO2 Nanofilms with Ag and Au Nanoparticles 
 
N.E. Kornienko, T.O. Busko, N.P. Kulish 
 
Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601 Kyiv, Ukraine 
 
(Received 18 June 2013; published online 03 September 2013) 
 
The nonmonotonic dependence of the intensities of vibrational lines in the Raman scattering of TiO 2 
nanofilms, including Ag and Au nanoparticles, from the irradiation dose D by Ti+ (140 keV) ions was estab-
lished. The increase of the intensity in 1.3-1.5 times for TiO2 films at D  1012 - 1013 ions/cm2 related with 
improved of films structure at low doses. The enhancement of low-frequency electronic bands with dose in-
creasing was study. It was shown that the effect of plasmon is not a major and the vibrational-electronic 
interaction plays the main function. 
 
Keywords: TiO2 Nanofilms, Ion Irradiation, Raman Scattering, Vibration Line, New Electronic Band. 
 
PACS numbers: 78.20._e, 78.30._j 
 
 
Titanium dioxide is widely known as a catalyst 
due to its high chemical stability. The doping of TiO2 
by Ag and Au nanoparticles (~20 nm) was carried out 
to improve the catalytic activity and shift of photoac-
tivity in the visible region. Anatase TiO2 nanofilms 
with thickness of ~ 200 nm on crystalline Si sub-
strate were obtained by the sol-gel method. The Ra-
man spectroscopy (RS) was used to study the chang-
es in the properties of both pure nanofilms TiO2, and 
composite systems TiO2/Ag, Au at ion Ti+ irradiation 
(with an energy of 140 keV). Raman spectra were 
obtained using a spectrometer Horbia Jobin Yvon 
T64000 with a cooled CCD-detector at 488 nm excita-
tion (power 2.1 mW, focusing ~ 1 µm). Radiation dos-
es D were changed from 1012 to 51014 ion/cm2. 
There is the distinctive and most intense vibrational 
mode Eg(1) at about ν1  143 cm-1 in the low-
frequency Raman spectra for anatase modification of 
TiO2. This mode corresponds to vibration of the 
bridges between ТіО6 octahedron and it’s very sensi-
tive to electron states change at ion irradiation and 
Ag, Au addition. This mode is very weak in rutile as 
ν2 mode in anatase.  The vibrational modes of ana-
tase are numbered in ascending order of frequency 
for the convenience. 
The weakening of the fundamental vibrational 
bands was observed based on the results of spectral 
studies of TiO2 nanofilms as well as the emergence 
and strengthening of new electronic states in the 
band gap at high ion implantation doses D.  Figure 1 
shows a selection of induced electronic bands in the 
Raman spectrum of nanofilms TiO2 at the highest 
dose of ion irradiation Dmax  51014 ions/cm2 and 
the difference spectrum at doses of 1013 ions/cm2 and 
Dmax with a negative polarity of the vibrational 
bands. The overlapping vibrational bands A1g and 
B1g of anatase denotes a frequency ν4, which is su-
perimposed on a very intense vibrational line sub-
strate νSi  520 cm-1. A similar wideband back-
ground is observed in the Raman spectra of compo-
site nanofilms TiO2/Ag, Au even in the absence of 
irradiation exposure. This is due to the influence of 
the plasmonic states of metal nanoparticles and its 
confirm the electronic nature of the broad bands, 
that are beginning in the narrow vibrational bands 
at irradiation.  
 
 
 
Fig. 1 – The appearance of broad and intense electronic bands 
in the Raman spectrum of TiO2 nanofilms with increasing 
irradiation dose and observation negative polarities of the 
vibrational bands of anatase in the difference between the 
observed spectra. 
 
We observed anomalously strong nonmonotonic de-
pendence of the vibrational bands ν1=143, ν3=396 and 
ν5  638 cm-1 intensities from the irradiation dose that 
normalized to the initial value of Ij(D  0) values shown 
in Fig.2. The intensity of the bands in the spectrum of 
TiO2 increased about 1.5 times at low doses (1012-1013 
ions/cm2), and at doses of Ti+ ions over 1014 ions/cm2 
appreciably weaken to less than I(D  0). Further 
weakening of bands ν1,5 to (0,2-0,6)I(D  0) is observed 
for nanofilms with nanoparticles Au and Ag. This is 
due to two opposite patterns of change in the collective 
energy states in radiation effects. The collectivization of 
the electronic states  increases at low doses, which is 
accompanied by catalytic activity increased, but at high 
doses Ti+ ions increases ionic interparticle bonds. The 
plasmon excitations contribut to increasing collectiviza-
tion of electronic states at D  0 in TiO2 films with Ag 
and Au nanoparticles, and the irradiation at 1013 
 N.E.Kornienko, T.O.Busko, N.P.Kulish PROC. NAP 2, 01PCSI25 (2013) 
 
 
01PCSI25-2 
ions/cm2 leads to weakening of the vibrational and elec-
tronic bands. This points to different mechanisms of 
the effects of plasma resonances and ion irradiation. 
The changing of the maximum intensity of the back-
ground of electronic bands IFmax for all studied systems 
shown in the inset in Figure 2. Thus, the increase in 
IFmax accompanied by a weakening of most vibrational 
bands. The strengthening of the band ν5  637 сm-1 for 
the composite system TiO2/Ag at Dmax is the exception.  
Its correlates with increased in catalytic activity as the 
maximum gain bands ν1,3,5  for pure TiO2 nanofilm with 
low doses. 
 
 
 
Fig. 2 – Dependence of the normalized peak intensities of 
vibrational bands ν1 (1) и ν5 (2) and the maximum intensity of 
the electron bands (inset) on the reduced irradiation dose 
D/Dmin (Dmin  1012 ion/cm2). 
 
An essential feature of the studied catalytic 
nanostructures is a significant increase in composite 
vibrational tones ν4-ν1 ≈ 230 сm-1; ν4-ν3 ≈ 120 сm-1 and 
overtones 2ν1 ≈ 280; 3ν1≈420 сm-1 with an increase in 
dosage irradiation by Ti+. This point to a strengthening 
of the vibrational anharmonicity and nonlinear suscep-
tibilities for the interaction of vibrational modes.The 
strengthening of the role of the higher vibrational 
states leads to the appearance of strong vibrational-
electronic interactions (VEI) [1]. This is due to the ap-
proach of the total high-frequency overtones and com-
posite tones to the electronic states and the interaction 
with them.This leads to a change in the electronic 
states, which is manifested in the intensity change of 
the vibration bands and the appearance of a fundamen-
tally new bands in the band gap. The observation of 
significant intensity broad electronic bands in irradiat-
ed by TiO2 films, shows that the effect of plasmon reso-
nance is not the main one. Their influence is one of the 
special cases of increased activity of the electronic 
states. The shift of the maxima of the vibrational bands 
and changes in their half width δν with radiation expo-
sure was studied. The parallel in the increase in ν1, δν1 
and δν5 with increasing of doses of radiation exposure, 
regardless of the presence of nanoparticles of Au and 
Ag, and the linear correlation δν1,5 and IFmax show that 
the main role in the phenomenon of radiation environ-
ments leads to increased activation of the nonlinear 
interaction of the vibrational modes and the strong 
VEI. 
 
 
REFERENCES 
 
1. N.E. Kornienko, Physics of the Alive 16 No1, 5-22 (2008). 
2. E. Kornienko, Bulletin of the University of Kiev, ser. fiz.-
mat. Science No3, 489 (2006). 
3. N.E. Kornienko, N.P. Kulish, S.A. Alekseev, O.P. Dmitrenko, 
E.L. Pavlenko, Optics and Spectroscopy 109 No5, 742 (2010). 
4. N.Е. Kornienko, N.L. Sheiko, O.N. Kornienko, 
T.Yu. Nikolaienko, Ukr.J.Phys. 58, 151 (2013).  


Variation of the Vibration and Electronic States at Ion Irradiation of TiO2 Nanofilms with Ag and Au Nanoparticles

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 2 No 1, 01PCSI25(2pp) (2013)   2304-1862/2013/2(1)01PCSI25(2) 01PCSI25-1  2013 Sumy State University Variation of the Vibration and Electronic States at Ion Irradiation of TiO2 Nanofilms with Ag and Au Nanoparticles  N.E. Kornienko, T.O. Busko, N.P. Kulish  Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601 Kyiv, Ukraine  (Received 18 June 2013; published online 03 September 2013)  The nonmonotonic dependence of the intensities of vibrational lines in the Raman scattering of TiO 2 nanofilms, including Ag and Au nanoparticles, from the irradiation dose D by Ti+ (140 keV) ions was estab-lished. The increase of the intensity in 1.3-1.5 times for TiO2 films at D  1012 - 1013 ions/cm2 related with improved of films structure at low doses. The enhancement of low-frequency electronic bands with dose in-creasing was study. It was shown that the effect of plasmon is not a major and the vibrational-electronic interaction plays the main function.  Keywords: TiO2 Nanofilms, Ion Irradiation, Raman Scattering, Vibration Line, New Electronic Band.  PACS numbers: 78.20._e, 78.30._j   Titanium dioxide is widely known as a catalyst due to its high chemical stability. The doping of TiO2 by Ag and Au nanoparticles (~20 nm) was carried out to improve the catalytic activity and shift of photoac-tivity in the visible region. Anatase TiO2 nanofilms with thickness of ~ 200 nm on crystalline Si sub-strate were obtained by the sol-gel method. The Ra-man spectroscopy (RS) was used to study the chang-es in the properties of both pure nanofilms TiO2, and composite systems TiO2/Ag, Au at ion Ti+ irradiation (with an energy of 140 keV). Raman spectra were obtained using a spectrometer Horbia Jobin Yvon T64000 with a cooled CCD-detector at 488 nm excita-tion (power 2.1 mW, focusing ~ 1 µm). Radiation dos-es D were changed from 1012 to 51014 ion/cm2. There is the distinctive and most intense vibrational mode Eg(1) at about ν1  143 cm-1 in the low-frequency Raman spectra for anatase modification of TiO2. This mode corresponds to vibration of the bridges between ТіО6 octahedron and it’s very sensi-tive to electron states change at ion irradiation and Ag, Au addition. This mode is very weak in rutile as ν2 mode in anatase.  The vibrational modes of ana-tase are numbered in ascending order of frequency for the convenience. The weakening of the fundamental vibrational bands was observed based on the results of spectral studies of TiO2 nanofilms as well as the emergence and strengthening of new electronic states in the band gap at high ion implantation doses D.  Figure 1 shows a selection of induced electronic bands in the Raman spectrum of nanofilms TiO2 at the highest dose of ion irradiation Dmax  51014 ions/cm2 and the difference spectrum at doses of 1013 ions/cm2 and Dmax with a negative polarity of the vibrational bands. The overlapping vibrational bands A1g and B1g of anatase denotes a frequency ν4, which is su-perimposed on a very intense vibrational line sub-strate νSi  520 cm-1. A similar wideband back-ground is observed in the Raman spectra of compo-site nanofilms TiO2/Ag, Au even in the absence of irradiation exposure. This is due to the influence of the plasmonic states of metal nanoparticles and its confirm the electronic nature of the broad bands, that are beginning in the narrow vibrational bands at irradiation.     Fig. 1 – The appearance of broad and intense electronic bands in the Raman spectrum of TiO2 nanofilms with increasing irradiation dose and observation negative polarities of the vibrational bands of anatase in the difference between the observed spectra.  We observed anomalously strong nonmonotonic de-pendence of the vibrational bands ν1=143, ν3=396 and ν5  638 cm-1 intensities from the irradiation dose that normalized to the initial value of Ij(D  0) values shown in Fig.2. The intensity of the bands in the spectrum of TiO2 increased about 1.5 times at low doses (1012-1013 ions/cm2), and at doses of Ti+ ions over 1014 ions/cm2 appreciably weaken to less than I(D  0). Further weakening of bands ν1,5 to (0,2-0,6)I(D  0) is observed for nanofilms with nanoparticles Au and Ag. This is due to two opposite patterns of change in the collective energy states in radiation effects. The collectivization of the electronic states  increases at low doses, which is accompanied by catalytic activity increased, but at high doses Ti+ ions increases ionic interparticle bonds. The plasmon excitations contribut to increasing collectiviza-tion of electronic states at D  0 in TiO2 films with Ag and Au nanoparticles, and the irradiation at 1013  N.E.Kornienko, T.O.Busko, N.P.Kulish PROC. NAP 2, 01PCSI25 (2013)   01PCSI25-2 ions/cm2 leads to weakening of the vibrational and elec-tronic bands. This points to different mechanisms of the effects of plasma resonances and ion irradiation. The changing of the maximum intensity of the back-ground of electronic bands IFmax for all studied systems shown in the inset in Figure 2. Thus, the increase in IFmax accompanied by a weakening of most vibrational bands. The strengthening of the band ν5  637 сm-1 for the composite system TiO2/Ag at Dmax is the exception.  Its correlates with increased in catalytic activity as the maximum gain bands ν1,3,5  for pure TiO2 nanofilm with low doses.    Fig. 2 – Dependence of the normalized peak intensities of vibrational bands ν1 (1) и ν5 (2) and the maximum intensity of the electron bands (inset) on the reduced irradiation dose D/Dmin (Dmin  1012 ion/cm2).  An essential feature of the studied catalytic nanostructures is a significant increase in composite vibrational tones ν4-ν1 ≈ 230 сm-1; ν4-ν3 ≈ 120 сm-1 and overtones 2ν1 ≈ 280; 3ν1≈420 сm-1 with an increase in dosage irradiation by Ti+. This point to a strengthening of the vibrational anharmonicity and nonlinear suscep-tibilities for the interaction of vibrational modes.The strengthening of the role of the higher vibrational states leads to the appearance of strong vibrational-electronic interactions (VEI) [1]. This is due to the ap-proach of the total high-frequency overtones and com-posite tones to the electronic states and the interaction with them.This leads to a change in the electronic states, which is manifested in the intensity change of the vibration bands and the appearance of a fundamen-tally new bands in the band gap. The observation of significant intensity broad electronic bands in irradiat-ed by TiO2 films, shows that the effect of plasmon reso-nance is not the main one. Their influence is one of the special cases of increased activity of the electronic states. The shift of the maxima of the vibrational bands and changes in their half width δν with radiation expo-sure was studied. The parallel in the increase in ν1, δν1 and δν5 with increasing of doses of radiation exposure, regardless of the presence of nanoparticles of Au and Ag, and the linear correlation δν1,5 and IFmax show that the main role in the phenomenon of radiation environ-ments leads to increased activation of the nonlinear interaction of the vibrational modes and the strong VEI.   REFERENCES  1. N.E. Kornienko, Physics of the Alive 16 No1, 5-22 (2008). 2. E. Kornienko, Bulletin of the University of Kiev, ser. fiz.-mat. Science No3, 489 (2006). 3. N.E. Kornienko, N.P. Kulish, S.A. Alekseev, O.P. Dmitrenko, E.L. Pavlenko, Optics and Spectroscopy 109 No5, 742 (2010). 4. N.Е. Kornienko, N.L. Sheiko, O.N. Kornienko, T.Yu. Nikolaienko, Ukr.J.Phys. 58, 151 (2013).  

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Variation of the Vibration and Electronic States at Ion Irradiation of TiO2 Nanofilms with Ag and Au Nanoparticles

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