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1.
Seisuke Nakashima Koji Sugioka Katsumi Midorikawa 《Applied Physics A: Materials Science & Processing》2011,104(3):993-996
We have demonstrated spatially selective modification of the magnetic properties of transparent iron-oxide-doped glass by
femtosecond- (fs-) laser irradiation and subsequent annealing. A near-infrared fs-laser beam with a wavelength of 775 nm was
focused 1 mm below the surfaces of glass samples. This produces absorption peaks due to the formation of hole-trap centers
in the irradiated region. Transparency was recovered after annealing at 450°C. A ferrimagnetic component was observed in the
M–H curve even at room temperature, whereas the diamagnetic component dominated in the M–H curve of the as-prepared glass sample. This indicates that fs-laser irradiation enhanced the magnetization in the irradiated
area. The irradiated and annealed glass sample also exhibited superparamagnetic blocking in the temperature dependence of
the magnetization with a blocking temperature higher than room temperature. This change in magnetism is presumably due to
local crystallization of ferrimagnetic nanoparticles, such as magnetite, induced by fs-laser irradiation and annealing. The
magnetic and optical properties of glass that had been annealed but not irradiated by a fs-laser beam remained unchanged. 相似文献
2.
A. I. Kupchishin A. D. Muradov Zh. A. Omarbekova B. G. Taipova 《Russian Physics Journal》2007,50(2):153-160
Joint effect of high-energy electrons, mechanical loads, and temperature on polyimide films of thicknesses in the range 30–130
μm is investigated. The films were preliminary irradiated by electrons in air using an éLU-6 linear accelerator with energy
of 2 MeV and doses D = 1, 5, 10, 20, 30, 40, and 100 MGy and then subjected to uniaxial mechanical tension at temperatures
(T) from 293 to 593 K. It is established that at T = 293–450 K and D = 20–40 MGy, the mechanical load causes almost the same
deformations (εl max) of nonirradiated and irradiated samples; at T = 450–550 K, deformations of films sharply increase, and the character of
their dependence changes. The εl max value of the initial sample increases almost linearly with temperature by a factor of 10, whereas the character of changing
εl max(T) of the irradiated films is more complex, and its value increases approximately by a factor of 4. For T > 500 K, the deformation
reaches limiting values. Irradiation increases the intensity of IR-spectra by 2–6 times and essentially increases the widths
of absorption bands at 720, 1380, and 1775 cm−1, which is caused by the formation of hydrogen bonds and cycles with nitrogen as well as by the formation of nitrogen oxides.
External loading applied to film rupture causes an increase in the EPR signal amplitude from 3·103 to 5·103, which is connected with an increased concentration of radicals =N-H and-NH
2. The electron irradiation of the polyimide films with their subsequent mechanical loading causes the spectrum lines to displace
from 3475.0 to 3512.5 cm−1 with simultaneous reduction of the signal amplitude from 6·103 to 4·103.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 52–58, February, 2007. 相似文献
3.
K. Schouteden P. Lievens C. Van Haesendonck 《Applied Physics A: Materials Science & Processing》2009,96(2):409-413
The structural stability of rapidly solidified (about 104 K/s) Sn–3.7Ag–0.9Zn eutectic solder was explored by high-temperature annealing. For the as-cast solders, the applied fast
cooling rate had a significant influence on the microstructure of the solders. The faster the applied cooling rates, the smaller
the β-Sn dendrites. After annealing at 473 K for 20 and 50 h, β-Sn dendrites congregated together into bulk ones for minimizing the interfacial energy, and Ag3Sn intermetallic compounds (IMCs) as well as ternary Ag–Zn–Sn IMCs segregated on the grain boundary of the β-Sn dendrites. It seems that the coarsening of the β-Sn dendrites in the rapidly solidified specimen brought a significant softening during annealing of the explored Sn–Ag–Zn
alloy. Finally, the β-Sn dendrites vanished gradually with increase of the annealing period, which leads to a kind of softening. 相似文献
4.
Our group has been investigating the effects related to radiation damage of CCDs since 1998. In a series of measurements in
2003 we found the puzzling effect of very slow filling of charge traps created by radiation damage of the silicon device.
In 2005 we intended to study this phenomenon in detail. However, while in 2003 we could see all the traps created by neutron
irradiation in 1998–1997 unchanged, such traps unexpectedly almost completely disappeared in 2005. We explain this as an effect
of annealing induced by electron irradiation, as in 2003 we irradiated with electrons the same device irradiated with neutrons
in 1997–1998. Results of the 2005 measurements are presented.
相似文献
5.
A new model of irradiation-induced disordering of semiconductors is proposed. According to this model, the disordered regions
capable of self-annealing are stabilized by self-localized electronic excitations (electrons, holes, excitons). Pulsed annealing
of these regions occurs through recombination of the electronic stoppers and dispersal of disordered regions thus takes place.
This model agrees well with the experiments on amorphisation and laser pulse annealing.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 67–72, April 2006. 相似文献
6.
At 4.2 K, the photoluminescence spectra of Cu(In,Ga)Se2 films irradiated by electrons with an energy of 5 MeV displayed the 0.93-and 0.79-eV bands that owe their origin to the radiative
recombination of nonequilibrium charge carriers on radiation-induced defects. The position of the energy levels of the defects
is determined and their nature is discussed.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 805–808, November–December, 2005. 相似文献
7.
X. Y. Tao I. Fsaifes V. Koncar C. Dufour C. Lepers L. Hay B. Capoen M. Bouazaoui 《Applied Physics A: Materials Science & Processing》2009,96(3):741-749
Indium tin oxide (ITO) thin films prepared by the sol–gel method have been deposited by the dip-coating process on silica substrates. CO2 laser is used for annealing treatments. The electrical resistivity of sol–gel-derived ITO thin films decreased following
crystallization after exposure to CO2 laser beam. The topological and electrical properties of the irradiated surfaces have been demonstrated to be strongly related
to the coating solution and to the laser processing parameters. Optimal results have been obtained for 5 dip-coating layers
film from 0.4 mol/l solution irradiated by 0.6 W/m2 laser power density. In this case, homogeneous and optically transparent traces were obtained with a measured sheet resistance
of 1.46×102 Ω/□. 相似文献
8.
I. Kh. Abdukadyrova 《Journal of Applied Spectroscopy》2007,74(2):278-282
Features of the thermoradiative changes in the optical absorption and luminescence spectra of leucosapphire (colorless sapphire)
crystals irradiated by neutron fluences within the range 5·1015 to 5·1019 cm−2 have been studied in the visible region. The stepwise character of these processes was established as well as the basic steps
involved in bleaching the induced color of the wafers as a result of isochronal annealing. Some anomalies have been observed
in the temperature dependence of the optical density of the 460–620 nm bands, the activation energies for the color centers
as well as the color center concentrations have been calculated, and the nature of the radiation-induced centers has been
analyzed. An analytical expression is proposed to describe the accumulation kinetics for the centers during irradiation of
the crystals by reactor neutrons. It is concluded that there is an interconnection between, for example, the 460 nm color
centers and the 540 nm luminescence centers, and that there is a common mechanism for the process of radiation-induced defect
formation, initially responsible for their formation in the crystal. The possible effect of reabsorption of radiation on the
behavior of the Y(Φ) curve in the irradiated material is discussed.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 247–251, March–April, 2007. 相似文献
9.
S. A. Mikhnov 《Journal of Applied Spectroscopy》1999,66(6):994-998
It has been found that the F-band of optical absorption which is observed in ψ-irradiated NaF crystals consists of three overlapping
bands. The band at 345 nm of width 40 nm is independent of the impurity composition of the crystals; it disappears upon exposure
to radiation at 345 nm and appears again upon annealing at 460±15 K for 15 min. This band is correlatable in intensity with
the superfine structure of an EPR spectrum. The width (65–110 nm) and the spectral position (355–375 nm) of the second band
depend on the impurity composition of the crystal. The band of width 90–110 nm at 320–325 nm disappears upon annealing and
appears after exposure to light simultaneously with the disappearance of an EPR signal. It is established that the band at
345 nm is caused by quasimolecules based on fluorine atoms, that at 355–375 nm is triggered by F-centers with a different
impurity composition near the haloid vacancy, and the band at 320–325 nm owes its appearance to F-centers in a negatively
charged state (F′).
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70 F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 6, pp. 849–853, November–December, 1999. 相似文献
10.
The initial stage of faceting on the tungsten (110) vicinal plane during annealing in conditions close to thermodynamic equilibrium
or favoring thermal-diffusion-assisted mass transport is studied by scanning tunneling microscopy. In the first case, the
initial nanofacets (the traces left after electrochemical polishing) arrayed at a repeat frequency q=(3–4)·105 cm−1 merge to form microsteps with clearly pronounced faceting. In the second, the nanofacet pattern is overlaid by a wavelike,
sinusoidally corrugated structure. The corrugation frequency is in a good agreement with the theoretical estimate obtained
within the surface mass-transport model.
Fiz. Tverd. Tela (St. Petersburg) 39, 968–971 (June 1997) 相似文献
11.
Dambarudhar Mohanta Fouran Singh D. K. Avasthi Amarjyoti Choudhury 《Central European Journal of Physics》2006,4(2):187-195
Semiconductor nanoparticles (CdS) were fabricated by an inexpensive chemical route using polyvinyl alcohol (PVA) as the dielectric
host matrix. Nano-CdS in PVA were subjected to ion irradiation (using oxygen, chlorine and gold) in the medium energy range
(80–100 MeV) and under fluence variation of 1011–1013 ions/cm2. The nature of light emission was found to be drastically different in each of the three cases. Photoluminescence spectra
of oxygen irradiated samples exhibit band edge emission (2.8 eV) as well as trap related emission (1.76 eV) whereas band edge
emission is found to be bleached out for chlorine ion irradiated nano-CdS. The intense broad PL peaks, noticeable in the case
of gold ion irradiated samples suggest superposition of the two peaks — namely, band edge emission and trap related emission.
Furthermore, in the case of gold ion irradiated nano-CdS, energy shift in the PL spectra reveals variation in size distribution
caused by the extra pressure effect of heavy gold ion beams. The mechanism of such a difference as a result of ion irradiation-type
and ion-fluence is discussed in detail. 相似文献
12.
A. K. Kadashchuk N. I. Ostapenko N. A. Davidenko N. G. Kuvshinskii N. V. Lukashenko 《Physics of the Solid State》1997,39(7):1047-1051
This paper reports an investigation into the features of geminate recombination of long-lived electron-hole pairs in films
of poly(N-epoxypropylcarbazole) (PEPC) containing intramolecular charge transfer compounds as centers of photogeneration of charge
carriers carried out by measuring the attenuation kinetics of isothermal recombination luminescence over a wide range of temperatures
(4.2–300 K) for times t>1 s, along with the kinetics of photoinduced EPR signals. A study is made of how the presence of a potential barrier to the
reverse transition of carriers to the recombination center and the initial triplet state of the charged pairs affects the
geminate recombination. It is established that the kinetics of isothermal recombintation luminescence attenuation follow the
law I(t)∝t
−m
for the times under study, where m takes values from 0.65 to 1.05. The first observations of a nonmonotonic change in m with temperature are reported (m passes through a minimum at a certain temperature), and a mechanism is proposed for recombination of charged pairs in PEPC
containing intramolecular charge-transfer compounds as an explanation for this phenomenon.
Fiz. Tverd. Tela (St. Petersburg) 39, 1183–1187 (July 1997) 相似文献
13.
S.D. Cheng X.Q. Han C.H. Kam Y. Zhou Y.L. Lam J.T. Oh X.W. Xu T.C. Chong 《Applied Physics A: Materials Science & Processing》2001,73(4):511-514
We have successfully prepared highly c-axis-textured LiNbO3 films on hydrogen-terminated Si (111) substrate using sol-gel spin-coating and rapid thermal annealing. These highly c-axis-textured
films were obtained with a preheating at 300 °C for 15 min followed by a rapid thermal annealing at 500–700 °C for 120 s.
The c-axis orientation of the LiNbO3 film is due to a weak effect caused by the 3-fold symmetry match between the film and the Si (111) substrate. The c-axis
orientation of LiNbO3 films is very useful in integrated optics devices and metal–ferroelectric–semiconductor nonvolatile memory applications.
Received: 15 September / Accepted: 4 December / Published online: 3 April 2001 相似文献
14.
A. É. Bugrov S. Yu. Gus’kov V. B. Rozanov I. N. Burdonskii V. V. Gavrilov A. Yu. Gol’tsov E. V. Zhuzhukalo N. G. Koval’skii V. N. Kondrashov M. I. Pergament V. M. Petryakov S. D. Tsoi 《Journal of Experimental and Theoretical Physics》1999,88(3):441-448
We have experimentally investigated the interaction of high-power neodymium laser pulses in the intensity range 1013–1014 W/cm2 with flat low-density (0.5–10 mg/cm3) agar-agar targets under conditions of interest for problems of inertial nuclear fusion. Optical and x-ray methods with high
temporal and spatial resolution were used to examine the dependence of absorption and scattering of the incident beam on the
initial mean density and thickness of the irradiated samples. We show that when a porous target is irradiated, a bulk absorption
layer of high-temperature plasma is produced inside the target whose dimensions are determined by the initial density of the
material. The time dependence and spectral composition of the harmonics 2ω
0 and 3ω
0/2 observed in the plasma-scattered radiation are measured. A theoretical model is developed that describes the interaction
of high-power laser pulses with a porous medium. Predictions of the model, based on the hypothesis of two stages of homogenization
of the target material—a fast stage (0.1–0.3 ns) and a slow stage (1–3 ns), are in good agreement with the experimental data.
Zh. éksp. Teor. Fiz. 115, 805–818 (March 1999) 相似文献
15.
F. P. Korshunov T. P. Larionova A. V. Mudryi A. I. Patuk I. A. Shakin 《Journal of Applied Spectroscopy》1999,66(3):410-414
Using low-temperature (4.2–78 K) photoluminescence, we study the processes of defect formation in silicon films on sapphire
irradiated with high-energy particles (electrons, γ-quanta of60Co). It is established that carbon atoms, as a residual process impurity, participate in the formation of luminescence centers
stable up to annealing temperatures of about 550 K. For carbon-containing centers we reveal a shift in the spectral lines
relative to their position in spectra of single-crystal silicon. It is proposed that this spectral shift is associated with
the presence of internal stresses of about 5·108 N/m2 in the silicon films.
Institute of Solid-State Physics and Semiconductors, National Academy of Sciences of Belarus, 17, P. Brovka Str., Minsk, 220072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskefii, Vol. 66, No. 3, pp. 383–386, May–June, 1999. 相似文献
16.
F. Machalett K. Edinger J. Melngailis M. Diegel K. Steenbeck E. Steinbeiss 《Applied Physics A: Materials Science & Processing》2000,71(3):331-335
For direct writing of electrically conducting connections and areas into insulating gold oxide thin films a scanning Ar+ laser beam and a 30 keV Ga+ focused ion beam (FIB) have been used. The gold oxide films are prepared by magnetron sputtering under argon/oxygen plasma.
The patterning of larger areas (dimension 10–100 μm) has been carried out with the laser beam by local heating of the selected
area above the decomposition temperature of AuOx (130–150 °C). For smaller dimensions (100 nm to 10 μm) the FIB irradiation could be used. With both complementary methods
a reduction of the sheet resistance by 6–7 orders of magnitude has been achieved in the irradiated regions (e.g. with FIB
irradiation from 1.5×107 Ω/□ to approximately 6 Ω/□). The energy-dispersive X-ray analysis (EDX) show a considerably reduced oxygen content in the
irradiated areas, and scanning electron microscopy (SEM), as well as atomic force microscopy (AFM) investigations, indicate
that the FIB patterning in the low-dose region (1014 Ga+/cm2) is combined with a volume reduction, which is caused by oxygen escape rather than by sputtering.
Received: 30 May 2000 / Accepted: 31 May 2000 / Published online: 13 July 2000 相似文献
17.
A.V. Osipov P. Patzner P. Hess 《Applied Physics A: Materials Science & Processing》2006,82(2):275-280
The growth of ultra-thin (<6 nm) silicon-dioxide films on Si(100):H, Si(111):H, and a-Si:H surfaces in a dry oxygen atmosphere
(0.1–10 Pa) at low temperatures (35–200 °C) was investigated. Oxidation was induced by pulsed F2-laserradiation at 157 nm. The thickness and composition of the growing films were monitored in real time by spectroscopic
ellipsometry in the photon energy range of 1.15–4.75 eV. The kinetics of low-temperature oxidation was similar for the Si
surfaces investigated and differs from that of high-temperature thermal oxidation (900–1200 °C) that can be described by the
Deal–Grove model. To explain the faster growth at the initial stage, it is proposed that oxidation occurs by diffusion of
oxygen atoms O and/or ions O-rather than oxygen molecules. The recombination of diffusive species to oxygen molecules limits their penetration into the
bulk. A diffusion model is developed for low-temperature oxidation which takes into account the recombination process of the
diffusive species. Good agreement between theory and experiment is found. The activation energy of diffusion of the active
species was found to be 0.15 eV, in agreement with previous results and recent calculations for O- ions.
PACS 82.65.+r; 07.60.Fs; 81.65.Mq; 82.50.Hp 相似文献
18.
Hardening in Fe–Cr–Mo-alloys due to the formation of σ-phase, has been the subject of theoretical and experimental interest.
In the present investigation Fe–Cr-alloys containing 0, 2, 4 and 6% Mo were prepared and were fully transformed to the σ-phase
by isothermally annealing the samples for various periods at temperatures of 600–800oC. After each annealing cycle room temperature
CEMS-spectra were recorded and micro-hardness tests were performed. The micro-hardness increases with annealing time and temperature,
in accordance with the fraction of σ-phase present, and ranged from about 140 HV to 200 HV. From the measurements, activation
energies were also deduced.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
19.
P. Haro-González I. R. Martín S. González-Pérez L. L. Martin F. Lahoz D. Puerto J. Solís 《Applied Physics A: Materials Science & Processing》2010,98(4):879-884
Localized modification of the optical properties of erbium doped strontium barium niobate (SBN) glass has been performed using
femtosecond laser irradiation. The samples, with composition SrO–BaO–Nb2O5–B2O5 and doped with 5%mol of Er3+, were fabricated using a melt-quenching method. The samples were irradiated with different number of pulses per spot (1–50
pulses) at two different laser fluences (2.6 and 5.6 J/cm2) by using an fs laser amplifier operating at 800 nm and generating pulses with a duration of 120 fs.
Micro-luminescent microscopy, using an Ar+ laser as excitation source, has been used to analyze the modifications of the luminescent properties of the sample upon fs
laser exposure. The emissions of the Er3+: 4I11/2→4I15/2 and 4I13/2→4I15/2 transitions allow appreciating the structural modifications caused by femtosecond laser exposure. The lifetimes of the levels
involved in these transitions were measured inside and outside the laser irradiated region. These measurements have been compared
with those obtained in bulk glass ceramic sample, which is obtained from the glass precursor by a thermal treatment in order
to estimate the optimal conditions to produce nanocrystals in a localized region by ultrafast laser irradiation. 相似文献
20.
T. V. Sokolova O. N. Chaikovskaya É. A. Sosnin I. V. Sokolova 《Journal of Applied Spectroscopy》2006,73(5):632-639
We have used fluorescence spectroscopy to study photoconversions of 2-methylphenol (2-MP), 4-methylphenol (4-MP), and 2-amino-4-methylphenol
(2-A-4-MP) in water when excited by UV radiation from different sources. We discuss the effect of the acidity of the medium
and dissolved oxygen on photoconversions of the indicated methylphenols. The photodegradation efficiency for 2-MP and 4-MP
decreases in the absence of oxygen. The photoconversion efficiency for methylphenols in alkaline medium is higher when irradiated
by light with λrad = 283 nm, while in neutral medium it is higher when irradiated by light with λrad = 222 nm.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 5, pp. 566–572, September–October, 2006. 相似文献