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1.
Tingyin Ning Cong Chen Yueliang Zhou Heng Lu Dongxiang Zhang Hai Ming Guozhen Yang 《Applied Physics A: Materials Science & Processing》2009,94(3):567-570
CaCu3Ti4O12 (CCTO) thin films were successfully prepared on LaAlO3 substrates by pulsed laser deposition technique. We measured the nonlinear optical susceptibility of the thin films using
Z-scan method at a wavelength of 532 nm with pulse durations of 25 ps and 7 ns. The large values of the third-order nonlinear
optical susceptibility, χ
(3), of the CCTO film were obtained to be 2.79×10−8 esu and 3.30×10−6 esu in picosecond and nanosecond time regimes, respectively, which are among the best results of some representative nonlinear
optical materials. The origin of optical nonlinearity of CCTO films was discussed. The results indicate that the CCTO films
on LaAlO3 substrates are promising candidate materials for applications in nonlinear optical devices. 相似文献
2.
We prepared polycrystalline AgInSe2 thin films by vacuum evaporation on glass substrate at a high temperature using the stoichiometric powder. The thin films were characterized by X-ray diffraction and UV-vis-NIR spectroscopy. The samples were subjected to the irradiation of 1.26 MeV protons (H+). The effect of irradiation on the optical properties has been investigated for different doses of H+. It is observed that the band gap of silver indium selenide thin films decreases gradually with ion irradiation dose. 相似文献
3.
G.S. Wang X.J. Meng Z.Q. Lai J. Yu J.L. Sun S.L. Guo J.H. Chu 《Applied Physics A: Materials Science & Processing》2003,76(1):83-86
Ferroelectric Bi3.25La0.75Ti3O12 (BLT) thin films have been grown on Pt/Ti/SiO2/Si substrates by chemical solution methods. X-ray diffraction analysis shows that BLT thin films are polycrystalline with
(171)-preferential orientation. Atomic force microscopy investigation shows that they have large grains about 120 nm in size.
A Pt/BLT/Pt capacitor has been fabricated and showed excellent ferroelectricity, with a remnant polarization and coercive
field of 24 μC/cm2 and 116 kV/cm, respectively. The capacitor shows no polarization fatigue up to 109 switching cycles. The optical constants (n,k) of the BLT thin films in the wavelength range 0.35–1.7 μm were obtained by
spectroscopic ellipsometry measurements, and the band-gap energy was found to be about 3.25 eV.
Received: 16 October 2001 / Accepted: 6 January 2002 / Published online: 3 June 2002
RID="*"
ID="*"Corresponding author. Fax: +86-21/65830-734, E-mail: gswang@mail.sitp.ac.cn 相似文献
4.
5.
I. V. Kedyk P. Mathey G. Gadret A. A. Grabar K. V. Fedyo I. M. Stoika I. P. Prits Y. M. Vysochanskii 《Applied physics. B, Lasers and optics》2008,92(4):549-554
In this work we report results on electro-physical, optical and photorefractive investigations for Sb-doped Sn2P2S6 crystals. The crystals are obtained by two methods: the vapour-transport technique and the Bridgman technique using stoichiometric
Sn2P2S6 composition with different amounts of antimony in the initial compound. The good optical quality of the crystals obtained
with the Bridgman technique is underlined. The dependences of the photorefractive two-beam coupling coefficient and the grating
build-up time are investigated at the wavelength of 633 nm. It is found that the sample doped with 1.5% of Sb is characterized
by an optimal combination of the main photorefractive parameters exhibiting a fairly high two-beam coupling coefficient (up
to 20 cm−1) and a short response time (1.3 ms) that is the shortest among all the previously studied Sn2P2S6 crystals in the red spectral region. 相似文献
6.
T. Rudolf Ch. Kant F. Mayr M. Schmidt V. Tsurkan J. Deisenhofer A. Loidl 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,68(2):153-160
We studied the optical properties of antiferromagnetic ZnCr2Se4 by infrared spectroscopy up to 28,000 cm-1 and for temperatures from 5 to 295 K. At the magnetic phase transition at 21 K, one of the four phonon modes reveals a clear
splitting of 3 cm-1 as a result of spin-phonon coupling, the other three optical eigenmodes only show shifts of the eigenfrequencies. The antiferromagnetic
ordering and the concomitant splitting of the phonon mode can be suppressed in a magnetic field of 7 T. At higher energies
we observed a broad excitation band which is dominated by a two-peak-structure at about 18,000 cm-1 and 22,000 cm-1, respectively. These energies are in good agreement with the expected spin-allowed crystal-field transitions of the Cr3+ ions. The unexpected strength of these transitions with d-d character is attributed to a considerable hybridization of the
selenium p with the chromium d orbitals. 相似文献
7.
Hao Wang Y. Wang J. Feng C. Ye B. Y. Wang H. B. Wang Q. Li Y. Jiang A. P. Huang Z. S. Xiao 《Applied Physics A: Materials Science & Processing》2008,93(3):681-684
High-k gate dielectric hafnium dioxide films were grown on Si (100) substrate by pulsed laser deposition at room temperature. The
as-deposited films were amorphous and that were monoclinic and orthorhombic after annealed at 500°C in air and N2 atmosphere, respectively. After annealed, the accumulation capacitance values increase rapidly and the flat-band voltage
shifts from −1.34 V to 0.449 V due to the generation of negative charges via post-annealing. The dielectric constant is in
the range of 8–40 depending on the microstructure. The I–V curve indicates that the films possess of a promising low leakage
current density of 4.2×10−8 A/cm2 at the applied voltage of −1.5 V. 相似文献
8.
B. Xu X. Li J. Sun L. Yi 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,66(4):483-487
Using first-principles calculations based on density-functional theory in
its local-density approximation, we investigated the Electronic structure,
ferroelectricity and optical properties of CaBi2Ta2O9 (CBT)
for the first time. It is found that CBT compound has an indirect band gap
of 3.114 eV and the O 2s and 2p states are strongly hybridized with the 6s
states of Bi which belong to the (Bi2O2)2+ planes. The quite
strong Ta–O and Bi–O hybridization is the primary source for
ferroelectricity. Our results imply that the interaction between Bi and O is
highly covalent. The anisotropy occurs mainly above 4 eV in the optical
properties. The different optical properties have been discussed. 相似文献
9.
Al<Subscript>2</Subscript>O<Subscript>3</Subscript> plasma production during pulsed laser deposition
F. Caridi L. Torrisi A. M. Mezzasalma G. Mondio A. Borrielli 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):467-472
A Nd:YAG laser operating in second harmonic (532 nm), 3 ns pulse duration, 150 mJ pulse energy, and 10 Hz repetition rate,
is employed to irradiate Al2O3 target placed in high vacuum. The produced plasma is investigated by an ion collector used in time-of-flight configuration
and by a mass quadrupole spectrometer, in order to determine the equivalent plasma temperature and the atomic and molecular
composition. Pulsed laser deposition technique has been used to produce thin films on different substrates placed close to
the target. Different surface analyses, such as energy dispersive X-ray fluorescence (EDXRF), X-ray photoelectron spectroscopy
(XPS) and surface profilometry are employed to characterize the produced films. Measurements of ablation yield, plasma equivalent
temperature, acceleration voltage and characterization of grown thin films are presented and discussed. 相似文献
10.
S. A. Ahmed 《Applied Physics A: Materials Science & Processing》2008,92(3):565-570
Thermoelectric power and electrical resistivity measurements on polycrystalline samples of Bi2Se3 and stoichiometric ternary compound in the quasi-binary system SnSe–Bi2Se3 in the temperature range of 90–420 K are presented and explained assuming the existence of an impurity band. The variation
of the electron concentration with temperature above 300 K is explained in terms of the thermal activation of a shallow donor,
by using a single conduction band model. The density of states effective mass m
*=0.15m
0 of the electrons, the activation energy of the donors, their concentration, and the compensation ratio are estimated. The
temperature dependence of the electron mobility in conduction band is analyzed by taking into account the scattering of the
charge carriers by acoustic phonon, optical phonon, and polar optical phonon as well as by alloy and ionized impurity modes.
On the other hand, by considering the two-band model with electrons in both the conduction and impurity bands, the change
in the electrical resistivity with temperature between 420 and 90 K is explained. 相似文献
11.
L. Kovács M. Mazzera E. Beregi R. Capelletti 《Applied physics. B, Lasers and optics》2009,94(2):273-277
Several weak absorption bands have been observed in the optical absorption spectra of pure and rare-earth-doped YAl3(BO3)4 single crystals in the 3350– 3650 cm−1 wave number region. Two of them, peaking at about 3377 cm−1 and 3580 cm−1 in the 8 K spectra, appear in most of the samples. They are tentatively attributed to the stretching mode of OH− ions incorporated in the crystal during the growth. An additional absorption band at about 5250 cm−1 at 8 K has also been detected in almost all samples. The temperature and polarization dependences of these bands, and their
possible origin, are discussed. 相似文献
12.
L. Nedelcu A. Ioachim M. I. Toacsan M. G. Banciu I. Pasuk M. Buda N. Scarisoreanu V. Ion M. Dinescu 《Applied Physics A: Materials Science & Processing》2008,93(3):675-679
Ba0.6Sr0.4TiO3 (BST) bulk ceramic synthesized by solid state reaction was used as target for thin films grown by pulsed laser deposition
(PLD) and radiofrequency beam assisted PLD (RF-PLD). The X-ray diffraction patterns indicate that the films exhibit a polycrystalline
cubic structure with a distorted unit cell. Scanning Electron Microscopy investigations showed a columnar microstructure with
size of spherical grains up to 150 nm. The capacitance–voltage (C–V) characteristics of the BST films were performed by applying
a DC voltage up to 5 V. A value of 280 for dielectric constant and 12.5% electrical tunability of the BST capacitor have been
measured at room temperature. 相似文献
13.
Guang Yang Aiping Chen Ming Fu Hua Long Peixiang Lu 《Applied Physics A: Materials Science & Processing》2011,104(1):171-175
By controlling the oxygen pressure, single-phase CuO and Cu2O thin films have been obtained on quartz substrates using a pulsed laser deposition technique. The structure properties and
linear optical absorption of the films were characterized by X-ray diffraction and UV–VIS spectroscopy. By performing z-scan measurements using a femtosecond laser (800 nm, 50 fs), the real and imaginary parts of the third-order nonlinear susceptibility,
Re χ
(3) and Im χ
(3), of the films were determined. Both CuO and Cu2O films exhibited large optical nonlinearities, which is comparable to those in some representative semiconductor films such
as ZnO and GaN films using femtosecond laser excitation. Compared with Cu2O films, the CuO films showed larger third-order nonlinear optical effects under off-resonance excitation. Furthermore, the
mechanisms of the optical nonlinearities in CuO and Cu2O films are explained in the main text. It was suggested that the reasons of the difference in their nonlinear refractive
effects may be related to the different electronic structure in CuO and Cu2O materials. 相似文献
14.
Vasily Lavrentiev Jiri Vacik Hiroshi Naramoto Kazumasa Narumi 《Applied Physics A: Materials Science & Processing》2009,95(3):867-873
The structure transformation occurring in fullerene film under bombardment by 50 keV C60+ cluster ions is reported. The Raman spectra of the irradiated C60 films reveal a new peak rising at 1458 cm−1 with an increase in the ion fluence. This feature of the Raman spectra suggests linear polymerization of solid C60 induced by the cluster ion impacts. The aligned C60 polymeric chains composing about 5–10 fullerene molecules have been distinguished on the film surface after the high-fluence
irradiation using atomic force microscopy (AFM). The surface profiling analysis of the irradiated films has revealed pronounced
sputtering during the treatment. The obtained results indicate that the C60 polymerization occurs in a deep layer situated more than 40 nm below the film surface. The deep location of the C60 polymeric phase indirectly confirms the dominant role of shock waves in the detected C60 phase transformation. 相似文献
15.
F. Pfuner J. G. Analytis J.-H. Chu I. R. Fisher L. Degiorgi 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,67(4):513-517
We report on a thorough optical investigation of BaFe2As2 over a broad spectral range and as a function of temperature, focusing our attention on its spin-density-wave (SDW) phase
transition at TSDW = 135 K. While BaFe2As2 remains metallic at all temperatures, we observe a depletion in the far infrared energy interval of the optical conductivity
below TSDW, ascribed to the formation of a pseudogap-like feature in the excitation spectrum. This is accompanied by the narrowing of
the Drude term consistent with the dc transport results and suggestive of suppression of scattering channels in the SDW state.
About 20% of the spectral weight in the far infrared energy interval is affected by the SDW phase transition. 相似文献
16.
D. Do S. S. Kim S. W. Yi J. W. Kim 《Applied Physics A: Materials Science & Processing》2009,94(3):697-701
Ferroelectric and dielectric properties of bilayered ferroelectric thin films, SrBi4Ti4O15 grown on Bi4Ti3O12, were investigated. The thin films were annealed at 700°C under oxygen atmosphere. The bilayered thin films were prepared
on a Pt(111)/Ti/SiO2/Si substrate by a chemical solution deposition method. The dielectric constant and dielectric loss of the bilayered thin
films were 645 and 0.09, respectively, at 100 kHz. The value of remnant polarization (2P
r) measured from the ferroelectric thin film capacitors was 60.5 μC/cm2 at electric field of 200 kV/cm. The remnant polarization was reduced by 22% of the initial value after 1010 switching cycles. The results showed that the ferroelectric and dielectric properties of the SrBi4Ti4O15 on Bi4Ti3O12 ferroelectric thin films were better than those of the SrBi4Ti4O15 grown on a Pt-coated Si substrate suggesting that the improved properties may be due to the different nucleation and growth
kinetics of SrBi4Ti4O15 on the c-axis-oriented Bi4Ti3O12 layer or on the Pt-coated Si substrate. 相似文献
17.
The absorption spectra, fluorescence spectrum and fluorescence decay curve of Nd3+ ions in CaNb2O6 crystal were measured at room temperature. The peak absorption cross section was calculated to be 6.202×10−20 cm2 with a broad FWHM of 7 nm at 808 nm for E//a light polarization. The spectroscopic parameters of Nd3+ ions in CaNb2O6 crystal have been investigated based on Judd-Ofelt theory. The parameters of the line strengths Ω
t
are Ω
2=5.321×10−20 cm2,Ω
4=1.734×10−20 cm2,Ω
6=2.889×10−20 cm2. The radiative lifetime, the fluorescence lifetime and the quantum efficiency are 167 μs, 152 μs and 91%, respectively. The fluorescence branch ratios are calculated to be β
1=36.03%,β
2=52.29%,β
3=11.15%,β
4=0.533%. The emission cross section at 1062 nm is 9.87×10−20 cm2. 相似文献
18.
Tian Yu Tang Sheng Qiang Ren Yuan Liu Jing Quan Zhang Cai Liu Li Li Wu Wen Wu Wang Wei Li Liang Huan Feng 《Russian Journal of Physical Chemistry B, Focus on Physics》2018,12(3):503-509
Zn2SnO4 (ZTO) is a stable semiconductor in ZnO–SnO2 system and important transparent conducting oxide (TCO) predominantly used in optoelectronic devices. ZTO thin films were prepared by RF magnetron sputtering using Zn2SnO4 ceramic target in this paper. The effects of annealing temperatures and oxygen contents on characterization of ZTO thin films were studied. The results show that ZTO thin films prepared by RF magnetron sputtering are amorphous with an optical band gap of 3.22 eV. After annealing at 650°C in Ar atmosphere for 40 min, ZTO films possess a spinel structure with an optical band gap of 3.62 eV. The atomic force microscope (AFM) data of morphology reveals that the surface roughness of films is about 2 nm. The results of energy dispersive spectrometer (EDS) show that the concentration ratio of Zn to Sn is in the range from 1.44 to 1.57. The results of Hall-effect-measurement system reveal that the resistivity of films varies from 102 to 10–1 Ωcm, carrier concentration is about 1017 cm–3, and mobility ranges from 100 to 101 cm2 v–1 s–1. 相似文献
19.
K. SrinivasaRao B. Rajini Kanth P. K. Mukhopadhyay 《Applied Physics A: Materials Science & Processing》2009,96(4):985-990
Ultra-thin MoO3 films were deposited onto glass and Si substrates by r.f. magnetron sputtering. The optical and IR properties of the films
were studied in the range of 250 to 1000 nm and 400 to 1500 cm−1, respectively. The optical transmission spectra show a significant shift in absorption edge. The energy gap of the films
deposited at 373 K and 0.1 mbar was found to be 3.93 eV, and it decreases with increasing substrate temperature and decreasing
sputtering pressure. The IR transmittance spectra shows strong modes of vibrations of Mo=O and Mo–O–Mo units of MoO3 molecule. A significant change in energy gap and a shift in frequency of IR modes were observed in ultra-thin MoO3 films. 相似文献
20.
X.T. Li P.Y. Du H. Ye C.L. Mak K.H. Wong 《Applied Physics A: Materials Science & Processing》2008,92(2):397-400
Textured LixNi2-xO (LNO) thin films have been fabricated on (001)MgO substrates by pulsed laser deposition technique. The as-deposited LNO
films shows a conductivity of 2.5×10-3 Ω m and possess a transmittance of about 35% in the visible region. Subsequent deposition of Sr0.6Ba0.4Nb2O6 (SBN60) thin film on these LNO-coated MgO substrates resulted in a textured SBN layer with a 〈001〉 orientation perpendicular
to the substrate plane. Phi scans on the (221) plane of the SBN layer indicated that the films have two in-plane orientations
with respect to the substrate. The SBN unit cells were rotated in the plane of the film by ± 8.2° as well as ± 45° with respect
to the LNO/MgO substrate. Besides the highly (00l)-orientation, the SBN films also exhibited a dense microstructure as shown
by scanning electron microscopy. The electro-optic coefficient (r33) of the SBN film was measured to be 186 pm/V. On the basis of our results, we have demonstrated that the LNO film can be
used as a buffer layer as well as a transparent bottom electrode for waveguide applications. The SBN/LNO heterostructure is
also a suitable candidate for integrated electro-optics devices.
PACS 42.79.Gn; 42.82.Et; 78.20.Ci 相似文献