共查询到20条相似文献,搜索用时 148 毫秒
1.
Atomic mixing of Ni2O3/SiO2, NiO/SiO2, and Ni/SiO2 interfaces induced by swift heavy ion irradiation
B. Schattat W. Bolse S. Klaumünzer F. Harbsmeier A. Jasenek 《Applied Physics A: Materials Science & Processing》2003,76(2):165-169
We have investigated the interface mixing of Ni2O3/SiO2, NiO/SiO2, and Ni/SiO2 induced by the irradiation with Ar, Kr and Xe ions of energies ranging from 90 MeV to 260 MeV. Since these energies are in
the electronic stopping regime, atomic transport processes will not be directly initiated by elastic ion–target collisions,
but need to be excited by secondary processes like electron–phonon coupling or Coulomb explosion. Nevertheless, we have observed
a strong mixing effect in the ceramic systems if the electronic energy loss exceeds a certain threshold value. Estimation
of an effective diffusion constant indicates that diffusion takes place in the molten ion track. In contrast to the ceramics,
the metallic Ni layer is still insensitive even for the highest electronic stopping power used (Se=28 keV/nm) and does not exhibit mixing with its SiO2 substrate.
In addition, NiO/SiO2 and Ni/SiO2 were irradiated in the nuclear stopping regime with 600 keV Kr and 900 keV Xe–ions. Here the intermixing effect is in good
agreement with the assumption of ballistic atomic transport.
Received: 5 February 2002 / Accepted: 11 February 2002 / Published online: 3 May 2002
RID="*"
ID="*"Corresponding author. Fax: +49-711/685-3866, E-mail: bolse@ifs.physik.uni-stuttgart.de 相似文献
2.
Crunteanu A. Jänchen G. Hoffmann P. Pollnau M. Buchal C. Petraru A. Eason R.W. Shepherd D.P. 《Applied Physics A: Materials Science & Processing》2003,76(7):1109-1112
We present a method for the selective two- and three-dimensional patterning of sapphire using light ion-beam implantation
to generate severe lattice damage to depths exceeding 1 μm and subsequent selective wet chemical etching of the damaged regions
by hot H3PO4. C-cut sapphire crystals were implanted through contact masks using ion fluences of 1×1016 to 5×1017 He+/cm2 and energies up to 400 keV. The etching process is characterized by a high selectivity and a rate of approximately 19 nm/min.
Whereas an implantation that produces a continuously damaged pathway results in complete etching from the surface, sole in-depth
implantation using only high-energy ions leads to under-etching of the crystalline surface layer. By a combination of these
processes we have fabricated three-dimensional structures such as channels and bridges in sapphire.
Received: 14 October 2002 / Accepted: 15 October 2002 / Published online: 26 February 2003
RID="*"
ID="*"Corresponding author. Fax +41-21/693-3701, E-mail: aurelian.crunteanustanescu@epfl.ch 相似文献
3.
C. Ronning 《Applied Physics A: Materials Science & Processing》2003,77(1):39-50
Opposite to most other deposition methods, the dominating nucleation and growth mechanism during ion-beam deposition of energetic
ions in the range between 10 eV and 10 keV occurs in a region of a few nanometers below the surface of the growing film. This
process is called ‘subplantation’ – emphasizing the implantation of ions into a subsurface region. Ordering and phase formation
is a result of the interaction of the deposited ions with the solid state that takes place within the short time scale of
femto- and picoseconds. This extreme non-equilibrium process can result in metastable amorphous or crystalline structures.
This review will present several examples of the influence of the deposition parameters on the properties of diamond-like
materials synthesized using mass-selected ion-beam deposition. Furthermore, several existing models of the deposition process
will be presented and critically discussed.
Received: 11 November 2002 / Accepted: 12 November 2002 / Published online: 4 April 2003
RID="*"
ID="*"Corresponding author. Fax: +49-551/39-4493, E-mail: carsten.ronning@phys.uni-goettingen.de 相似文献
4.
We developed a high-power oscillator–regenerative amplifier femtosecond laser system. Based on chromium-doped forsterite.
The system is operating near 1.25 μm at a 5–10 kHz repetition rate. Chirped-pulse amplification produced 0.86 W (0.75 W) of
average power, or 465 mW (400 mW) after compression at 5 kHz (10 kHz). Nearly bandwidth-limited pulses of duration 135 fs
(shortest) and 150 fs (typical) are available with an energy of 93 μJ and 40 μJ at 5 and 10 kHz, respectively.
Received: 7 June 2002 / Published online: 15 November 2002
RID="*"
ID="*"Corresponding author. Fax: +49-30/63921289, E-mail: petrov@mbi-berlin.de 相似文献
5.
M.R. Koblischka B. Hewener U. Hartmann A. Wienss B. Christoffer G. Persch-Schuy 《Applied Physics A: Materials Science & Processing》2003,76(6):879-884
Microstructured thin-film elements with critical dimensions of 1 μm or less play an increasingly important role in magnetic
components for information technology applications. Devices that are directly based on such microstructures are key components
in magnetoelectronics for storage and sensor applications as well as modern concepts which are likely to substitute today’s
hard disk drives. Basic research on magnetic materials as well as industrial applications create an increasing demand for
high-resolution magnetic imaging methods. One such method is magnetic force microscopy (MFM). In spite of considerable achievements,
MFM also has some serious shortcomings, which have not been overcome to date. Under normal circumstances, the method yields
only qualitative information about the magnetic object and it is difficult to improve the resolution to values below 100 nm.
In this paper, we will report on advanced MFM probe preparation, based on electron beam methods, and discuss the possibilities
for batch fabrication of such advanced MFM tips. We show that the advanced probes allow high-resolution imaging of fine magnetic
structures within thin-film permalloy elements without perturbing them. Additionally, we present high-frequency MFM measurements
on a hard disk write head.
Received: 2 September 2002 / Accepted: 2 September 2002 / Published online: 5 March 2003
RID="*"
ID="*"Corresponding author. Fax: +49-681/302-3790, E-mail: m.koblischka@mx.uni-saarland.de 相似文献
6.
We examine in detail the theory of the intrinsic non-linearities in the dynamics of trapped ions due to the Coulomb interaction.
In particular, the possibility of mode–mode coupling, which can be a source of decoherence in trapped ion quantum computation,
or can be exploited for parametric down-conversion of phonons, is discussed and conditions under which such coupling is possible
are derived.
Received: 8 November 2002 / Published online: 26 March 2003
RID="*"
ID="*"Permanent address: MIP, Université Pierre et Marie Curie and Département de Physique, école Normale Supérieure, 75005
Paris, France
RID="**"
ID="**"Corresponding author. Fax: +1-505/667-1931, E-mail: dfvj@lanl.gov 相似文献
7.
S.A. Nepijko M. Klais G. Schönhense N. Cramer Z. Celinski C.M. Schneider S. Zennaro N. Zema N.N. Sedov 《Applied Physics A: Materials Science & Processing》2003,76(5):809-815
Micromagnetic properties of the Fe19Ni81 (5 nm)/NiO (50 nm)/Fe19Ni81 (30 nm) structured system have been investigated in a photoemission electron microscope in the magnetic X-ray circular dichroism
operating mode. The microstructured Fe19Ni81 (5 nm) film contained two-dimensional islands with the aspect ratio varying from 1:1 to 10:1, and the linear size of their
long axis comprised 24, 12 and 6 μm. It is shown that the magnetic domains have the direction of magnetization preferentially
parallel and antiparallel to the magnetic field direction in which this system was prepared. Their number is determined by
the particles’ sizes, their shape as well as by the direction of the external magnetizing field and can be characterized by
a non-monotonic size dependence. The magnetization of domains with different lateral sizes was found to be 0.4 T with an accuracy
better than 20%.
Received: 29 May 2002 / Accepted: 17 July 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +49-6131/392-3807, E-mail: nepijko@mail.uni-mainz.de 相似文献
8.
W. Lieber X.S. Yi N. Nontasut D. Curticapean 《Applied physics. B, Lasers and optics》2002,75(4-5):487-491
The bandwidth behavior of graded-index multimode fibers (GI-MMFs) for different launching conditions is investigated to understand
and characterize the effect of differential mode delay. In order to reduce the launch-power distribution the near field of
a single-mode fiber is used to produce a controlled restricted launch. The baseband response is measured by observing the
broadening of a narrow input pulse (time-domain measurement). The paper verifies the degradation in bandwidth due to profile
distortion by scanning the spot of the single-mode fiber with a transversal offset from the center of the test sample. In
addition, the impact of the launch-power distribution tuned by different spot-size diameters is demonstrated. Measurements
were taken on ‘older’ 50-μm and 62.5-μm GI-MMFs as well as on laser-performance-optimized fibers more recently developed.
Received: 12 November 2001 / Final version: 26 June 2002 / Published online: 25 September 2002
RID="*"
ID="*"Corresponding author. Fax: +49-781/205-242, E-mail: opto@fh-offenburg.de 相似文献
9.
Hopp B. Smausz T. Kresz N. Nagy P.M. Juhász A. Ignácz F. Márton Z. 《Applied Physics A: Materials Science & Processing》2003,76(5):731-735
Allergic-type diseases are current nowadays, and they are frequently caused by certain metals. We demonstrated that the metal
objects can be covered by Teflon protective thin layers using a pulsed laser deposition procedure. An ArF excimer laser beam
was focused onto the surface of pressed PTFE powder pellets; the applied fluences were 7.5–7.7 J/cm2. Teflon films were deposited on fourteen-carat gold, silver and titanium plates. The number of ablating pulses was 10000.
Post-annealing of the films was carried out in atmospheric air at oven temperatures between 320 and 500 °C. The thickness
of the thin layers was around 5 μm. The prepared films were granular without heat treatment or after annealing at a temperature
below 340 °C. At 360 °C a crystalline, contiguous, smooth, very compact and pinhole-free thin layer was produced; a melted
and re-solidified morphology was observed above 420 °C. The adhesion strength between the Teflon films and the metal substrates
was determined. This could exceed 1–4 MPa depending on the treatment temperature. It was proved that the prepared Teflon layers
can be suitable for prevention of contact between the human body and allergen metals and so for avoidance of metal allergy.
Received: 12 June 2002 / Accepted: 13 June 2002 / Published online: 4 November 2002
RID="*"
ID="*"Corresponding author. E-mail: bhopp@physx.u-szeged.hu 相似文献
10.
We report on germania/organically modified silane (ormosil) hybrid materials produced by the sol–gel technique for photonic
applications. Acid-catalyzed solutions of γ-glycidoxypropyltrimethoxysilane mixed with germanium isopropoxide have been used
as precursors for the hybrid materials. Planar waveguide films with a thickness of about 2 μm have been prepared by a single
spin-coating process and low-temperature heat treatment from these high germanium content hybrid materials. Atomic force microscopy,
thermal gravimetric analysis, UV–visible spectroscopy, and Fourier-transform infrared spectroscopy have been used to investigate
the optical and structural properties of the films. The results have indicated that a dense, low absorption, and high transparency
(in the visible range) waveguide film could be achieved at a low temperature. A strong UV-absorption region at short wavelengths
∼200 nm, accompanied by a shoulder peaked at ∼240 nm, has been noticed due to the neutral oxygen monovacancy defects. The
propagation mode and loss properties of the planar waveguide films have also been investigated by using a prism-coupling technique.
Received: 5 November 2002 /
Revised version: 27 December 2002 / Published online: 19 March 2003
RID="*"
ID="*"Corresponding author. Fax: +65-67909081, E-mail: ewxque@ntu.edu.sg 相似文献
11.
C. Dölle C. Reinhardt P. Simon B. Wellegehausen 《Applied physics. B, Lasers and optics》2002,75(6-7):629-634
. Investigations of the efficient generation of powerful coherent radiation at 82.8 nm by frequency tripling of short-pulse
KrF laser radiation are presented. Argon gas is selected as nonlinear medium due to the resonantly enhanced 3rd-order susceptibility
χ(3)(-3ω,ω,ω,ω). Pulse energies of 100 μJ at 82.8 nm have been measured for a pump pulse energy of 14 mJ. An upscaling to more
than 500 μJ is expected with available more powerful pump lasers. Features of this XUV source and possible applications are
discussed.
Received: 26 July 2002 / Published online: 15 November 2002
RID="*"
ID="*"Corresponding author. Fax: +49-511/7622211, E-mail: reinhardt@iqo.uni-hannover.de 相似文献
12.
S.T. Sanders 《Applied physics. B, Lasers and optics》2002,75(6-7):799-802
A swept-wavelength source is created by connecting four elements in series: a femtosecond fiber laser at 1.56 μm, a non-linear
fiber, a dispersive fiber and a tunable spectral bandpass filter. The 1.56-μm pulses are converted to super-continuum (1.1–2.2 μm)
pulses by the non-linear fiber, and these broadband pulses are stretched and arranged into wavelength scans by the dispersive
fiber. The tunable bandpass filter is used to select a portion of the super-continuum as a scan-wavelength output. A variety
of scan characteristics are possible using this approach. As an example, an output with an effective linewidth of approximately
1 cm-1 is scanned from 1350–1550 nm every 20 ns. Compared to previous scanning benchmarks of approximately 1 nm/μs, such broad,
rapid scans offer new capabilities: a gas sensing application is demonstrated by monitoring absorption bands of H2O, CO2, C2H2 and C2H6O at a pressure of 10 bar.
Received: 5 August 2002 / Revised version: 23 September 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +1-608/265-2316, E-mail: ssanders@engr.wisc.edu 相似文献
13.
J. Békési J.-H. Klein-Wiele P. Simon 《Applied Physics A: Materials Science & Processing》2003,76(3):355-357
The generation of submicron-sized holes on metal surfaces by applying femtosecond UV laser pulses was investigated. Different
optical schemes based on a Schwarzschild-type reflective objective were used to reach optimized ablation quality and efficiency
in different applications (hole ablation, through-hole drilling, generation of surface patterns consisting of holes, etc.).
Submicron-sized holes and hole patterns were ablated onto metal surfaces and drilled through ∼5-μm-thick steel foils with
600-nm diameter on the output side. Using a special optical interferometric method, large-area surface processing of high-conductivity
materials in the submicron regime was performed. Combining these techniques with the application of high-repetition-rate ultra-short
UV laser sources, large-area sub-μm processing of all kinds of materials in industrial environments is possible.
Received: 28 February 2002 / Accepted: 12 March 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +49-551/503599, E-mail: psimon@llg.gwdg.de 相似文献
14.
Highly oriented GaN nanowire arrays have been achieved by the catalytic reaction of gallium with ammonium. The resulting materials
were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), energy dispersive X-ray
spectroscopy (EDS), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM images show
that the resulting materials are nanowire arrays with a uniform length of about 10 μm. XRD, EDS, TEM and SAED indicate that
the nanowire arrays are single-crystal hexagonal GaN with a wurtzite structure. They have diameters of 10 to 20 nm.
Received: 2 October 2002 / Accepted: 7 October 2002 / Published online: 17 December 2002
RID="*"
ID="*"Corresponding author. E-mail: wwwangjc@sina.com 相似文献
15.
L.E. Batay A.A. Demidovich A.N. Kuzmin A.N. Titov M. Mond S. Kück 《Applied physics. B, Lasers and optics》2002,75(4-5):457-461
A new laser medium – Yb,Tm:KY(WO4)2 – for diode pumped solid state laser applications operating around 1.9 to 2.0 μm has been investigated and the main laser
characteristics are presented. Diode pumping at 981 nm and around 805 nm was realised. For 981-nm pumping, the excitation
occurs into Yb3+ ions followed by an energy transfer to Tm3+ions. A slope efficiency of 19% was realised. For pumping around 805 nm, the excitation occurs directly into the Tm3+ ions. Here a maximum slope efficiency of 52%, an optical efficiency of 40%, and output powers of more than 1 W were realised.
Using a birefringent quartz plate as an intracavity tuning element, the tunability of the Yb,Tm:KY(WO4)2 laser in the spectral range of 1.85–2.0 μm has been demonstrated. The possibility of laser operation in a microchip cavity
configuration for this material has also been shown.
Received: 12 March 2002 / Revised version: 20 May 2002 / Published online: 25 September 2002
RID="*"
ID="*"Corresponding author. Fax: +49-531/592-4116, E-mail: stefan.kueck@ptb.de 相似文献
16.
We report on a passively Q-switched diode-pumped Nd:YVO4 laser polarized along the a axis (corresponding to the smallest value of emission cross section at 1064 nm), generating 157-μJ
pulses with 6.0-ns time duration (>20 kW peak power) and 3.6 W of average power at 1064 nm with good beam quality (M2<1.4). The selection of the polarization was performed by a novel technique relying on the birefringence of the laser crystal
and on the misalignment sensitivity of the resonator.
Received: 30 September 2002 /
Revised version: 22 November 2002 / Published online: 19 March 2003
RID="*"
ID="*"Corresponding author. Fax: +39-382/422583, E-mail: agnesi@ele.unipv.it 相似文献
17.
Copper nanowire arrays for infrared polarizer 总被引:10,自引:0,他引:10
Y.T. Pang G.W. Meng Y. Zhang Q. Fang L.D. Zhang 《Applied Physics A: Materials Science & Processing》2003,76(4):533-536
A micropolarizer of copper nanowire arrays within anodic alumina membrane (AAM) was fabricated by anodization of pure Al foil
and electrodeposition of Cu, respectively. X-ray diffraction, scanning electron microscopy and transmission electron microscopy
investigations reveal that the ordered Cu nanowires are essentially single crystal, and have an average diameter of 90 nm.
Spectrophotometer measurements show that the copper nanowire arrays embedded in AAM can only transmit polarized light vertical
to the wires. An extinction ratio of 24 to 32 dB and an average insertion loss of 0.5 dB in the wavelength range of 1 to 2.2 μm
were obtained, respectively. Therefore Cu nanowire/AAM can be used as a wire grid type micropolarizer.
Received: 28 January 2002 / Accepted:17 May 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +86-551/559-1434, E-mail: ytpang@263.net 相似文献
18.
Weisbuch F. Tokarev V.N. Lazare S. Débarre D. 《Applied Physics A: Materials Science & Processing》2003,76(4):613-620
A microscopic flow of a transient liquid film produced by KrF laser ablation is evidenced on targets of PET and PEN. Experiments
were done by using single pulses of the excimer laser beam micropatterned with the aid of submicron projection optics and
grating masks. The samples of various crystalline states, ablated with a grating-forming beam (period Λ=3.7 μm), were precisely
measured by atomic force microscopy, in order to evidence any deviation from the ablation behavior predicted by the current
theory (combination of ablation curve and beam profile). This was confirmed by comparing various behaviors dependent on the
polymer nature (PC, PET and PEN). PC is a normally ablating polymer in the sense that the ablated profile can be predicted
with previous theory neglecting liquid-flow effects. This case is called ‘dry’ ablation and PC is used as a reference material.
But, for some particular samples like crystalline PET, it is revealed that during ablation a film of transient liquid, composed
of various components, which are discussed, can flow under the transient action of the gradient of the pressure of the ablation
plume and resolidify at the border of the spot after the end of the pulse. This mechanism is further supported by a hydrodynamics
theoretical model in which a laser-induced viscosity drop and the gradient of the plume pressure play an important role. The
volume of displaced liquid increases with fluence (0.5 to 2 J/cm2) and satisfactory quantitative agreement is obtained with the present model. The same experiment done on the same PET polymer
but prepared in the amorphous state does not show microflow, and such an amorphous sample behaves like the reference PC (‘dry’
ablation). The reasons for this surprising result are discussed.
Received: 31 October 2002 / Accepted: 4 November 2002 / Published online: 22 January 2003
RID="*"
ID="*"Present address: ST Microelectronics, Crolles, France
RID="**"
ID="**"Corresponding author. Fax: +33-556/84-6645, E-mail: s.lazare@lpcm.u-bordeaux1.fr 相似文献
19.
M.W. Todd R.A. Provencal T.G. Owano B.A. Paldus A. Kachanov K.L. Vodopyanov M. Hunter S.L. Coy J.I. Steinfeld J.T. Arnold 《Applied physics. B, Lasers and optics》2002,75(2-3):367-376
A novel instrument, based on cavity-ringdown spectroscopy (CRDS), has been developed for trace gas detection. The new instrument
utilizes a widely tunable optical parametric oscillator (OPO), which incorporates a zinc–germanium–phosphide (ZGP) crystal
that is pumped at 2.8 μm by a 25-Hz Er,Cr:YSGG laser. The resultant mid-IR beam profile is nearly Gaussian, with energies
exceeding 200 μJ/pulse between 6 and 8 μm, corresponding to a quantum conversion efficiency of approximately 35%. Vapor-phase
mid-infrared spectra of common explosives (TNT, TATP, RDX, PETN and Tetryl) were acquired using the CRDS technique. Parts-per-billion
concentration levels were readily detected with no sample preconcentration. A collection/flash-heating sequence was implemented
in order to enhance detection limits for ambient air sampling. Detection limits as low as 75 ppt for TNT are expected, with
similar concentration levels for the other explosives.
Received: 1 April 2002 / Revised version: 13 June 2002 / Published online: 12 September 2002
RID="*"
ID="*"Corresponding author. Fax: +1-408/524-0551, E-mail: mtodd@picarro.com 相似文献
20.
Ultrashort-laser-pulse-driven rewritable phase-change optical recording in Sb-based films 总被引:1,自引:0,他引:1
This paper reviews the work we have carried out over the last years on the development of ultrashort-laser-pulse-driven, rewritable,
phase-change optical memories. The materials we have tailored for this application are non-stoichiometric, Sb-rich amorphous
thin films, which can be crystallized upon irradiation with ultrashort laser pulses, showing a large optical contrast upon
transformation. This result makes them very promising for the development of rewritable phase-change optical memories under
ultrashort pulses, since the reversibility of the process has also been demonstrated. Adequate control of the heat-flow conditions
has allowed us to achieve a full transformation time faster than 400 ps for crystallization/amorphization using 30-ps pulses.
The crystallization threshold fluence has been found to decrease upon irradiation with pulses shorter than 800 fs, thus suggesting
the relevance of high-electronic-excitation-induced processes in the amorphous-to-crystalline phase transition. This has been
confirmed by the observation of an ultrafast, non-thermal phase transition occurring 200–300 fs after the arrival of the laser
pulse at the surface, for fluences above the crystallization threshold. The presence of this transient phase conditions the
final state induced therefore enabling the applicability of this material as a rewritable recording medium using femtosecond
pulses.
Received: 11 October 2001 / Accepted: 9 July 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +34-91/564-5557, E-mail: J.Solis@io.cfmac.csic.es 相似文献