共查询到20条相似文献,搜索用时 0 毫秒
1.
H. Minami D. Manage Y.Y. Tsui R. Fedosejevs M. Malac R. Egerton 《Applied Physics A: Materials Science & Processing》2001,73(5):531-534
We have compared the quality of carbon films deposited with magnetically guided pulsed laser deposition (MGPLD) and conventional
pulsed laser deposition (PLD). In MGPLD, a curved magnetic field is used to guide the plasma but not the neutral species to
the substrate to deposit the films while, in conventional PLD, the film is deposited with a mixture of ions, neutral species
and clusters. A KrF laser pulse (248 nm) was focused to intensities of 10 GW/cm2 on a carbon source target and a magnetic field strength of 0.3 T was used to steer the plasma around a curved arc to the
deposition substrate. Electron energy loss spectroscopy was used in order to measure the fraction of sp3 bonding in the films produced. It is shown that the sp3 fraction, and hence the diamond-like character of the films, increased when deposited only with the pure ion component by
MGPLD compared with films produced by the conventional PLD technique. The dependence of film quality on the laser intensity
is also discussed.
Received: 7 December 2000 / Accepted: 20 August 2001 / Published online: 2 October 2001 相似文献
2.
T. Yu Y.-F. Chen Z.-G. Liu L. Sun S.-B. Xiong N.-B. Ming Z.-M. Ji J. Zhou 《Applied Physics A: Materials Science & Processing》1996,64(1):69-72
The semiconductive perovskite-type oxide SrFeO3-x (x<0.16) (SFO) thin films have been directly fabricated on (001)SrTiO3 and (001)LaAlO3 single crystal substrates by pulsed laser deposition(PLD) under high oxygen partial pressure of 100 Pa. The SFO thin films
were (110) oriented. The x-ray photoelectron spectroscopy (XPS) analysis showed that the surface of SFO thin film has strong
gas absorption capability. The resistance versus temperature has been measured in the temperature range from 77 K to 300 K.
The SFO thin film showed typical semiconductive property. Dependence of resistance of SFO thin film on oxygen pressure was
measured and result showed that the SFO thin film had better oxygen sensitive property.
Received: 14 May 1996/Accepted: 15 August 1996 相似文献
3.
J.M. Fernández-Pradas G. Sardin J.L. Morenza 《Applied Physics A: Materials Science & Processing》2003,76(2):251-256
Calcium phosphate coatings were deposited with a KrF excimer laser onto titanium alloy to study their homogeneity. Deposition
was performed at a high deposition rate under a water vapour atmosphere of 45 Pa and at a substrate temperature of 575 °C.
Samples were also submitted to annealing under the same conditions of deposition for different times just after deposition.
The effects of the annealing were also investigated. The morphology of the coatings was studied by scanning electron microscopy.
Their structure and phase distribution was analysed by X-ray diffractometry and infrared and micro-Raman spectroscopies. Besides
the non-uniform thickness, the results reveal an inhomogeneity in the spatial distribution of calcium phosphate phases in
the coatings. The phase distribution can be almost completely correlated with the deposition rate. High deposition rates (0.5 nm/pulse)
occurring in the centre of deposition results in the formation of amorphous calcium phosphate, while lower deposition rates
favour the presence of hydroxyapatite and alpha tricalcium phosphate. At intermediate deposition rates, beta tricalcium phosphate
is found, probably because the superimposed effect of energetic particles bombardment. The annealing process promotes the
crystallisation of the amorphous material. The importance of the deposition rate in the phases obtained is stated after comparing
these results with a previous work where homogeneous hydroxyapatite coatings were obtained under the same conditions of laser
fluence, temperature and pressure, but at lower deposition rates.
Received: 22 November 2001 / Accepted: 12 March 2002 / Published online: 5 July 2002
RID="*"
ID="*"Corresponding author. Fax: +34-93/402-1138, E-mail: jmfernandez@fao.ub.es 相似文献
4.
R.A. Gunasekaran J.D. Pedarnig M. Dinescu 《Applied Physics A: Materials Science & Processing》1999,69(6):621-624
A parametric study of the growth of La0.5Sr0.5CoO3 (LSCO) thin films on (100) MgO substrates by pulsed-laser deposition (PLD) is reported. Films are grown under a wide range
of substrate temperature (450–800 °C), oxygen pressure (0.1–0.9 mbar), and incident laser fluence (0.8–2.6 J/cm2). The optimum ranges of temperature, oxygen pressure, and laser fluence to produce c-axis oriented films with smooth surface morphology and high metallic conductivity are identified. Films deposited at low
temperature (500 °C) and post-annealed in situ at higher temperatures (600–800 °C) are also investigated with respect to their
structure, surface morphology, and electrical conductivity.
Received: 20 November 1998 / Accepted: 6 July 1999 / Published online: 21 October 1999 相似文献
5.
M. Morcrette A. Gutiérrez-Llorente A. Laurent J. Perrière P. Barboux J.P. Boilot O. Raymond T. Brousse 《Applied Physics A: Materials Science & Processing》1998,67(4):425-428
x La2/3+yTiO3-δ perovskite (with δ≤0.5) were deposited by the laser ablation technique from Li0.33La0.56TiO3 targets. Their growth onto MgO substrateswas studied as a function of the oxygen pressure. For films grown in vacuum (10-6 mbar), a La0.63TiO2.5 composition was obtained, meaning that Ti3+ alone is present in the films, while Li ions are not incorporated under these conditions. This material shows good electric
conductivity (ρ=500 mΩ cm). By contrast, insulating films with a Li0.1La0.70TiO3 composition corresponding to the Ti4+ species were obtained at high oxygen pressures (>0.05 mbar). For all conditions, textured films were grown with different
orientations depending on the temperature and the oxygen pressure.
Received: 10 September 1997/Accepted: 24 November 1997 相似文献
6.
S. Rey F. Antoni B. Prevot E. Fogarassy J.C. Arnault J. Hommet F. Le Normand P. Boher 《Applied Physics A: Materials Science & Processing》2000,71(4):433-439
Diamond-like carbon (DLC) films have been grown on Si substrates at ambient temperature by the pulsed-laser ablation technique,
using pulses of different durations both in the nano- and picosecond ranges and at various energy fluences. The stability
of these films was investigated as a function of thermal anneals performed in UHV conditions up to 1273 K. Their physico-chemical
properties have been characterized by different techniques including X-ray photo-emission, Auger electron and electron-energy-loss
spectroscopies, Raman scattering, spectroscopic ellipsometry and atomic-force microscopy. The thermal stability of the films
has been demonstrated to be related to their initial structural (sp3/sp2 ratio) and chemical (contaminant) properties. DLC layers prepared under optimized conditions have been found to show a very
good thermal stability up to 900 K.
Received: 4 Jule 2000 / Accepted: 6 July 2000 / Published online: 6 September 2000 相似文献
7.
The deposition rates of permalloy and Ag are monitored during pulsed laser deposition in different inert gas atmospheres.
Under ultrahigh vacuum conditions, resputtering from the film surface occurs due to the presence of energetic particles in
the plasma plume. With increasing gas pressure, a reduction of the particle energy is accompanied with a decrease of resputtering
and a rise in the deposition rate for materials with high sputtering yield. In contrast, at higher gas pressures, scattering
of ablated material out of the deposition path between target and substrate is observed, leading to a decrease in the deposition
rate. While in the case of Xe and Ar these processes strongly overlap, they are best separated in He. A He pressure of about
0.4 mbar should be used to reduce the kinetic energy of the deposited particles, to reach the maximum deposition rate and
to avoid implantation of the particles. This is helpful for the preparation of stoichiometric metallic alloy films and multilayers
with sharp interfaces.
Received: 27 March 2002 / Accepted: 3 April 2002 / Published online: 5 July 2002 相似文献
8.
X. Zhu S. Lu H.L.W. Chan C.L. Choy K.H. Wong 《Applied Physics A: Materials Science & Processing》2003,76(2):225-229
Compositionally graded (Ba1-xSrx)TiO3 (BST) (x:0.0∼0.25) thin films were grown on Pt (111)/TiO2/SiO2/Si (100) substrates using layer-by-layer pulsed laser deposition in the temperature range 550–650 °C. Both downgraded (Ba/Sr
ratio varying from 100/0 at the bottom surface to 75/25 at the top surface) and upgraded (Ba/Sr ratio varying from 75/25 at
the bottom surface to 100/0 at the top surface) BST films were prepared. Their microstructures were systematically studied
by X-ray diffractometry and scanning electron microscopy. A grain morphology transition from large ‘rosettes’ (>0.30 μm) to
small compact grains (70–110 nm) was observed in the downgraded BST films as the deposition temperature was increased from
550 to 650 °C. No such grain morphology transition was detected in the upgraded BST films. Dielectric measurements with metal
electrodes revealed an enhanced dielectric behavior in the downgraded films. This enhancement is mainly attributed to the
large compressive stress field built up near the interface between the downgraded film and substrate. Furthermore, the BaTiO3 layer in the downgraded BST films not only serves as a bottom layer but also as an excellent seeding layer for enhancing
the crystallization of the subsequent film layers in the downgraded films.
Received: 10 December 2001 / Accepted: 12 March 2002 / Published online: 19 July 2002
RID="*"
ID="*"Corresponding author. Fax: 86-25/359-5535, E-mail: xhzhu@public1.ptt.js.cn 相似文献
9.
Synthesis of nanocrystalline material by sputtering and laser ablation at low temperatures 总被引:1,自引:0,他引:1
P. Ayyub R. Chandra P. Taneja A.K. Sharma R. Pinto 《Applied Physics A: Materials Science & Processing》2001,73(1):67-73
Physical vapor deposition techniques such as sputtering and laser ablation – which are very commonly used in thin film technology
– appear to hold much promise for the synthesis of nanocrystalline thin films as well as loosely aggregated nanoparticles.
We present a systematic study of the process parameters that facilitate the growth of nanocrystalline metals and oxides. The
systems studied include TiO2, ZnO, γ-Al2O3, Cu2O, Ag and Cu. The mean particle size and crystallographic orientation are influenced mainly by the sputtering power, the substrate
temperature and the nature, pressure and flow rate of the sputtering gas. In general, nanocrystalline thin films were formed
at or close to 300 K, while loosely adhering nanoparticles were deposited at lower temperatures.
Received: 31 October 2000 / Accepted: 9 January 2001 / Published online: 26 April 2001 相似文献
10.
Z.Y. Chen J.P. Zhao T. Yano T. Ooie 《Applied Physics A: Materials Science & Processing》2002,75(2):213-216
Raman characteristics of carbon nitride films synthesized by nitrogen-ion-beam-assisted pulsed laser deposition were investigated.
In addition to the D (disorder) band and G (graphitic) band commonly observed in carbon nitride films, two Raman bands located
at 1080–1100 and 1465–1480 cm-1 were found from our carbon nitride films. These two bands were well matched with the predicted Raman frequencies for βC3N4 and the observed Raman bands reported for carbon nitride films, indicating their relation to carbon-nitrogen stretching vibrations.
Furthermore, the relative intensity ratio of the two Raman bands to the D and G bands increased linearly with increasing nitrogen
content of the carbon nitride films.
Received: 30 October 2000 / Accepted: 5 February 2001 / Published online: 2 October 2001 相似文献
11.
F. Kokai K. Yamamoto Y. Koga S. Fujiwara R.B. Heimann 《Applied Physics A: Materials Science & Processing》1998,66(4):403-406
x ) films in a nitrogen atmosphere within the range 5×10-4–4×10-1 Torr. In the presence of a magnetic field, the emission intensities of N2 (second positive system) and CN species in the graphite ablation plumes were altered significantly, depending on the pressure
of the N2 environment. Corresponding to an intense CN emission, a magnetic field-induced enhancement of N incorporation – for example,
up to 37% at an N2 pressure of 300 mTorr – and the formation of sp3 tetrahedral CN bonding were both observed in the films. This suggests that the arrival of CN species at the substrate surface
with kinetic energies is important for film deposition.
Received: 27 August 1997/Accepted: 8 September 1997 相似文献
12.
Y. Du M.-S. Zhang J. Wu L. Kang S. Yang P. Wu Z. Yin 《Applied Physics A: Materials Science & Processing》2003,76(7):1105-1108
SrTiO3 thin films were prepared on a fused-quartz substrate by pulsed laser deposition (PLD). Dense and homogeneous films with a
thickness of 260 nm were prepared. Optical constants (refractive index n and extinction coefficient k) were determined from
the transmittance spectra using the envelope method. The optical band gap energy of the films was found to be 3.58 eV, higher
than the 3.22 eV for bulk SrTiO3, attributable to the film stress exerted by the substrate. The dispersion relation of the refractive index vs. wavelength
follows the single electronic oscillator model. The refractive index and the packing density for the PLD-prepared SrTiO3 thin films are higher than those for the SrTiO3 films prepared by physical vapor deposition, sol–gel and RF sputtering.
Received: 18 March 2002 / Accepted: 7 October 2002 / Published online: 8 January 2003
RID="*"
ID="*"Corresponding author. Fax: +86-25/359-5535, E-mail: mszhang@nju.edu.cn 相似文献
13.
A. Sikora A. Berkesse O. Bourgeois J.-L. Garden C. Guerret-Piécourt A.-S. Loir F. Garrelie C. Donnet 《Applied Physics A: Materials Science & Processing》2009,94(1):105-109
We report on electrical measurements and structural characterization performed on boron-doped diamond-like carbon thin films
deposited by femtosecond pulsed laser deposition. The resistance has been measured between 77 and 300 K using four probe technique
on platinum contacts for different boron doping. Different behaviours of the resistance versus temperature have been evidenced
between pure DLC and boron-doped DLC. The a-C:B thin film resistances exhibit Mott variable range hopping signature with temperature.
Potential applications of DLC thin films to highly sensitive resistive thermometry is going to be discussed. 相似文献
14.
R. Dinu M. Dinescu J.D. Pedarnig R.A. Gunasekaran D. Bäuerle S. Bauer-Gogonea S. Bauer 《Applied Physics A: Materials Science & Processing》1999,69(1):55-61
Ferroelectric SrBi2Ta2O9 (SBT) films were grown by pulsed-laser deposition (PLD) at different substrate temperatures and fluences. A correlation between
film structure and ferroelectric properties is established. The dielectric function ε′ of thin SBT films shows a Curie–Weiss behavior well below the peak temperature Tmax and relaxor-like behavior in the vicinity of Tmax. Domain walls have a strong influence on the dielectric and ferroelectric properties and on the polarization fatigue of SBT
films below 100 °C. The formation of ferroelectric phases is favored at lower substrate temperatures by incorporating Bi2O3 template layers into the structure.
Received: 18 March 1999 / Accepted: 19 March 1999 / Published online: 5 May 1999 相似文献
15.
Thin films of the conducting polymer poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS) were deposited by resonant infrared laser vapor deposition (RIR-LVD). The PEDOT:PSS was frozen in various matrix solutions and deposited using a tunable, mid-infrared free-electron laser (FEL). The films so produced exhibited morphologies and conductivities that were highly dependent on the solvent matrix and laser irradiation wavelength used. When deposited from a native solution (1.3% by weight in water), as in matrix-assisted pulsed laser evaporation (MAPLE), films were rough and electrically insulating. When the matrix included other organic “co-matrices” that were doped into the solution prior to freezing, however, the resulting films were smooth and exhibited good electrical conductivity (0.2 S/cm), but only when irradiated at certain wavelengths. These results highlight the importance of the matrix/solute and matrix/laser interactions in the ablation process. 相似文献
16.
N. Huber J. Heitz D. Bäuerle R. Schwödiauer S. Bauer H. Niino A. Yabe 《Applied Physics A: Materials Science & Processing》2001,72(5):581-585
KrF excimer-laser ablation of sintered-powder polytetrafluoroethylene (PTFE) targets is used for the deposition of high-quality
PTFE films on metallic microstructures and metal backplates for electroacoustic applications. The films are found to be highly
crystalline, consisting of large spherulites with diameters up to 1 mm. X-ray photoelectron spectroscopy of the films revealed
the chemical similarity of press-sinter target pulsed-laser-deposited films with bulk PTFE. Negatively charged PTFE films
on stainless steel backplates exhibit an exceptional charge stability with practically no decrease of the surface potential
up to 225 °C in open-circuit thermally stimulated discharge.
Received: 20 December 2000 / Accepted: 20 December 2000 / Published online: 23 March 2001 相似文献
17.
V. Brien A. Dauscher P. Weisbecker F. Machizaud 《Applied Physics A: Materials Science & Processing》2003,76(2):187-195
The preparation in thin film form of the known icosahedral phase in Ti-Ni-Zr bulk alloys has been investigated as a function
of substrate temperature. Films were deposited by pulsed laser deposition on sapphire substrates at temperatures ranging from
room temperature to 350 °C. Morphological and structural modifications have been followed by grazing-incidence and θ–2θ X-ray
diffraction, transmission electron diffraction and imaging. Chemical composition has been analyzed by electron probe microanalysis.
The in-depth variation of composition has been studied by secondary neutral mass spectroscopy. We show that pulsed laser deposition
at 275 °C makes the formation of a 1-μm-thick film of Ti-Ni-Zr quasicrystalline textured nanocrystallites possible.
Received: 7 June 2001 / Accepted: 18 February 2002 / Published online: 3 June 2002
RID="*"
ID="*"Corresponding author. Fax: +33-3/8357-6300, E-mail: brien@mines.u-nancy.fr 相似文献
18.
A. Basillais C. Boulmer-Leborgne J. Mathias N. Laidani A. Laurent J. Perrière 《Applied Physics A: Materials Science & Processing》2000,71(6):619-625
We have studied the growth of Al nitride films by laser ablation in order to check the potential of the method. The influence
of process parameters such as nature of the target, laser energy density, nitrogen partial pressure, etc. on the composition,
chemical nature and structure of the films has been investigated. Rutherford backscattering spectrometry, nuclear reaction
analysis, X-ray diffraction and X-ray photoelectron spectroscopy were used to characterize the films. Literature reports on
AlN film growth by laser ablation but oxygen contamination is poorly discussed whereas it is the main problem encountered.
The origin of this contamination and the mechanisms of incorporation were studied, and the crucial parameter was found to
be the residual pressure during ablation. Due to the difference in chemical reactivity between oxygen and nitrogen atomic
species, to obtain pure AlN films it is necessary to increase the concentration of atomic nitrogen. Thus, a RF discharge device
was added allowing a better nitrogen molecule dissociation. Finally, despite composition deviations, the AlN phase can be
formed in the laser-deposited films. Highly textured films presenting epitaxial relationships with crystalline Al2O3 substrates can be grown even with a 10% oxygen concentration.
Received: 7 October 1999 / Accepted: 17 April 2000 / Published online: 13 September 2000 相似文献
19.
M. Jelinek J. Lančok M. Pavelka P.A. Atanasov A. Macková F. Flory C. Garapon 《Applied Physics A: Materials Science & Processing》2002,74(4):481-485
Nd: KGd(WO4)2 thin films were deposited by KrF laser ablation on MgO, YAP, YAG and Si substrates at temperatures up to 800 °C. Film crystallinity,
morphology, stoichiometry (WDX, RBS and PIXE), excitation spectra, fluorescence, refractive index and waveguiding properties
were studied in connection with deposition conditions. The best films were crystalline and exhibited losses of approximately
5 dB cm-1 at a wavelength of 633 nm.
Received: 8 January 2001 / Accepted: 7 November 2001 / Published online: 11 February 2002 相似文献
20.
This study investigated the optical and electrical properties of Nb-doped TiO2 thin films prepared by pulsed laser deposition (PLD). The PLD conditions were optimized to fabricate Nb-doped TiO2 thin films with an improved electrical conductivity and crystalline structure. XRD analyses revealed that the deposition at room temperature in 0.92 Pa O2 was suitable to produce anatase-type TiO2. A Nb-doped TiO2 thin film attained a resistivity as low as 6.7 × 10−4 Ω cm after annealing at 350 °C in vacuum (<10−5 Pa), thereby maintaining the transmittance as high as 60% in the UV-vis region. 相似文献