共查询到20条相似文献,搜索用时 15 毫秒
1.
J. Dubowik I. Gościańska Y. Kudryavtsev 《The European physical journal. Special topics》2008,158(1):113-118
We report on FMR experiments performed for the first time on thin Ni-Mn-Ga films clamped to the mica substrates and then fully
released from them. The aim is to evaluate the role of magnetoelastic coupling in stressed Ni-Mn-Ga Heusler alloy films that
undergo martensitic transformation. The experimental results show that the difference in the effective magnetization 4π(Meff tubes-Meff films) is negligible in the austenite phase and it increases to about 1–1.5 kG at temperatures well below the martensitic transformation.
The data suggests that magnetoelastic coupling in the martensite phase of Ni-Mn-Ga thin films is typical of normal thin magnetic
films with magnetostriction of about 50 ppm. 相似文献
2.
F. Khelfaoui M. Kohl J. Buschbeck O. Heczko S. Fähler L. Schultz 《The European physical journal. Special topics》2008,158(1):167-172
This paper reports on the fabrication and characterization of epitaxial Ni-Mn-Ga microactuators. Ni-Mn-Ga films are grown
on heated single-crystalline MgO substrates by DC magnetron sputtering. X-ray diffraction measurements demonstrate epitaxial
growth of the films. At room temperature, the crystal structure is identified to be non-modulated (NM) tetragonal martensite.
Electrical resistance measurements confirm that the films display the martensitic phase transformation well above the Curie
temperature TC of 325 K. Orientation-dependent magnetization measurements are performed to determine magnetic film properties. Micromachining
of the Ni-Mn-Ga films is performed on an alumina substrate covered by a temporary adhesive layer. A transfer bonding process
is developed to finally integrate the micromachined Ni-Mn-Ga structures to a target substrate in order to obtain NiMnGa microactuators
having freely movable microparts. Temperature-displacement characteristics demonstrate the actuation performance of epitaxial
NiMnGa microactuators for the first time. 相似文献
3.
B. Audoin M. Perton N. Chigarev C. Rossignol 《The European physical journal. Special topics》2008,153(1):235-237
Investigation of thin metallic film properties by means
of picosecond ultrasonics [C. Thomsen et al., Phys. Rev. Lett. 53, 989 (1984)] has been under the scope of several studies.
Generation of longitudinal and shear waves [T. Pézeril et al., Phys. Rev. B 73, 132301 (2006); O. Matsuda et al., Phys. Rev. Lett. 93, 095501 (2004)] with a wave vector normal
to the film free surface has been demonstrated. Such measurements cannot
provide complete information about properties of anisotropic films. Extreme
focusing of a laser pump beam (≈0.5 μm) on the sample surface
has recently allowed us to provide evidence of picosecond acoustic
diffraction in thin metallic films (≈1 μm) [C. Rossignol et al., Phys. Rev. Lett. 94, 166106 (2005)]. The resulting
longitudinal and shear wavefronts propagate at group velocity through the
bulk of the film. To interpret the received signals, source directivity
diagrams are calculated taking into account material anisotropy, optical
penetration, and laser beam width on the sample surface. It is shown that
acoustic diffraction increases with optical penetration, so competing with
the increasing of directivity caused by beam width. Reflection with mode
conversion at the film-substrate interface is discussed. 相似文献
4.
S. Gloor V. Romano W. Lüthy H.P. Weber V.V. Kononenko S.M. Pimenov V.I. Konov A.V. Khomich 《Applied Physics A: Materials Science & Processing》2000,70(5):547-550
Two-dimensional antireflective periodical microstructures for the IR range are fabricated on the surface of CVD diamond films.
These structures are created using an ArF excimer laser (λ=193 nm) and a direct writing scheme consisting of a beam collimator
and a microscope objective to focus the beam onto the sample. Two different arrays are investigated. One has a spacing of
3 μm and is produced with single shots and the other one has a spacing of 4 μm and is produced with three shots per spot.
The hole depth and shape are measured with an atomic force microscope (AFM). The optical transmittance and the scattering
properties of the structure at 10.6 μm are reported for a CO2 laser beam. With a spectrometer further transmission measurements in the range of 5 to 20 μm are performed.
Received: 16 September 1999 / Accepted: 11 October 1999 / Published online: 24 March 2000 相似文献
5.
M. K. Bhuyan F. Courvoisier H. S. Phing O. Jedrkiewicz S. Recchia P. Di Trapani J. M. Dudley 《The European physical journal. Special topics》2011,199(1):101-110
We report the generation of femtosecond Bessel beams of conical half-angle 26 degrees using an axicon lens and a beam reduction
imaging setup. The generated Bessel beams were applied to the micromachining of nanostructures in glass of length up to 100 μm.
The effect of the incident pulse energy on the characteristics of the nano- structures was studied using optical microscopy. 相似文献
6.
T.J. Rinke R.B. Bergmann J.H. Werner 《Applied Physics A: Materials Science & Processing》1999,68(6):705-707
Thermal crystallization of a double layer porous Si film creates a monocrystalline Si film with a thin separation layer between
the Si film and the reusable starting wafer. The process enables transfer of thin monocrystalline Si films to foreign substrates,
whereby devices may be formed before or after separation of the film. Sub-micrometer thick films are almost compact, while
films with a thickness of several μm contain voids, and are therefore termed “quasi-monocrystalline”. Internal voids strongly
enhance optical absorption by light scattering. The hole mobility is 78 cm2 V-1 s-1 at a p-type starting wafer resistivity of 0.05 Ω cm.
Received: 24 March 1999 / Accepted: 29 March 1999 / Published online: 5 May 1999 相似文献
7.
AMBIKA NEGI R V HARIWAL ANJU SEMWAL R G SONKAWEDE D KANJILAL J M S RANA R C RAMOLA 《Pramana》2011,77(4):707-714
In the present study, the effects of swift heavy ion beam irradiation on the structural, chemical and optical properties of
Makrofol solid-state nuclear track detector (SSNTD) were investigated. Makrofol-KG films of 40 μm thickness were irradiated with oxygen beam (O8 + ) with fluences ranging between 1010 ion/cm2 and 1012 ion/cm2. Structural, chemical and optical properties were investigated using X-ray diffraction, FTIR spectroscopy and UV–visible
spectroscopy methods. It is observed that the direct and indirect band gaps of Makrofol-KG decrease after the irradiation.
The XRD study shows that the crystalline size in the films decreases at higher fluences. The intensity plots of FTIR measurements
indicate the degradation of Makrofol at higher fluences. Roughness of the surface increases at higher fluence. 相似文献
8.
Cuicui Wang Ke Yu Lijun Li Qiong Li Ziqiang Zhu 《Applied Physics A: Materials Science & Processing》2008,90(4):739-743
Two kinds of ZnO nanotubes, including taper-like and flat-roofed tubes, have been successfully fabricated using a simple aqueous
solution route by changing the experimental conditions. All the obtained nanotubes have a uniform size of 500 nm in diameter,
10–50 nm in wall thickness, and 2–5 μm in length. The growth mechanism of two kinds of ZnO nanotubes was investigated. Field
emission measurements showed that tapering nanotubes have the good field emission performance with a low turn-on field of
∼ 2.1 V μm-1 and a low threshold field of ∼ 3.8 V μm-1, which suggests the possible applications of the ZnO tubular structures in field emission microelectronic devices.
PACS 73.61.Ga; 73.63. Fg; 85.45.Db 相似文献
9.
D. R. Lee S. H. Choi H. H. Lee J.-Y. Kim C.-J. Yu 《The European physical journal. Special topics》2009,167(1):163-169
We studied ~0.5 μm and 30–80 ? thick films of a normal dielectric
liquid, tetrakis(2-ethylhexoxy)silane (TEHOS), at temperature range 228–286 K,
deposited onto silicon (111) substrate with native oxide using X-ray
reflectivity. TEHOS is spherical with size ~10 ?, non-polar,
non-reactive, and non-entangling; TEHOS has been reported to show interfacial
layering at room temperature and surface layering at 0.23 Tc (Tc≈
950 K). For films m thick, the reflectivity data did not change
significantly as a function of temperature; for films 30–80 ? thick, the
reflectivity data did change. The data could be fitted with an electron density
model composed of a minimum necessary number of Gaussians and a uniform density
layer with error-function broadened interfaces. When the film thickness is 60–80 ? below 246 K, we found that the interface
and the surface layering coexist
but do not overlap. When the film thickness is 30–40 ? below 277 K, they
overlap and the electron density profile shows slowly decreasing molecular
oscillations at the air-liquid interface. 相似文献
10.
P. Bricault 《The European physical journal. Special topics》2007,150(1):227-232
The ISAC facility at TRIUMF utilizes up to 100 μA from the 500 MeV H- cyclotron to produce the RIB using the Isotopic Separation On Line (ISOL) method. The ISAC-I facility comprised the RNB production
target stations, the mass separator and the beam delivery to low energy area and to a room temperature linear accelerator
composed of a 4-rod RFQ and an inter-digital H type structure Drift Tube LINAC. ISAC-I linear accelerator can provide beam
from A = 3 to 30 amu with an energy range from 0.15 to 1.5 A MeV.
Since the beginning of operations target development program has been to increase proton beam currents on targets. Now we
routinely operate our target at 50 to 85 μA and recently we have operated our target at 100 μA. Other developments are in
place to add other ion sources, laser, FEBIAD and ECRIS to the actual surface ion source. The last two five year plans were
mainly devoted to the construction of a heavy ion superconducting LINAC (ISAC-II), that will upgrade the mass and the energy
range from 30 to 150 and 1.5 to 6.5 A MeV, respectively.
We are now commissioning the medium β section and first experiment is scheduled for the fall 2006. 相似文献
11.
Chien-Chon Chen Jin-Shyong Lin Eric Wei-Guang Diau Tzeng-Feng Liu 《Applied Physics A: Materials Science & Processing》2008,92(3):615-620
Self-cleaning of a surface of nanotube arrays of anodic titanium oxide (ATO) is demonstrated. The ATO was prepared in fluoride
ion containing sulfate electrolytes with a structure of 0.4 μm length, 100 nm pores diameter, 120 nm interpore distance, 25 nm
pore wall thickness, a 8×109 pores cm−2 pore density, and 68.2% porosity. Prepared as thin films either directly from a Ti foil or on a glass substrate, these arrays
have the property that water drops spread quickly over the surface of the films without irradiation. In contrast, a flat anatase
TiO2 film requires irradiation with UV light for several minutes before the contact angle decreases to zero. The observed self-cleaning
behavior of the ATO thin films is due to the capillary effect of the nanochannel structure and the superhydrophilic property
of the anatase TiO2 surface inside the tube. 相似文献
12.
H. Morawiec T. Goryczka J. Lelatko K. Prusik A. Drdzeń 《The European physical journal. Special topics》2008,158(1):93-98
Deformation of polycrystalline Ni-Mn-Ga alloys was
studied for both the L21 parent phase and 10 M martensitic state. The
effect of deformation by compression up to the fracture on mechanical
behavior and structure change was studied for the inhomogeneous as-cast
state and after annealing at 900○C for 50 hours. The structure, after
deformation of the parent phase, observed by TEM reveals the presence of 10 M
and 14 M martensite in the matrix, whereas the deformation of 10 M martensite
does not show the change of the structure type. The stress-strain curves
were analyzed and compared with the earlier published results. 相似文献
13.
P. Lemoine S.S. Roy J.P. Quinn P.D. Maguire J.A.D. McLaughlin 《Applied Physics A: Materials Science & Processing》2007,86(4):451-456
We present a comparative study where carbon nanostructures were prepared by electron and ion beam methods. Thin films of 10×10 μm2 area were prepared and analysed by Raman analysis, nanoindentation, energy dispersive X-ray analysis (EDX) and atomic force
microscopy (AFM). The material formed is not soft and graphitic, but of intermediate hardness (6–13 GPa) and with Raman spectral
features similar to those of hydrogenated amorphous carbon, although it contains a significant Ga content (up to 25 at. %).
This study was used to form sharp AFM supertip structures which were used to image sintered ceramic samples and films of aligned
carbon nanotubes. Compared to traditional Si tips, this gave an improved rendering of the sample’s aspect ratio although the
resolution is limited by the diameter of the C supertips.
PACS 81.05.Uw; 81.07.-b; 78.30.-j 相似文献
14.
Single beam laser-induced infrared photocarrier radiometry
(PCR) has been applied for measuring transport properties of H+
ion-implanted silicon samples. The contrast between the PCR signals inside
and outside the area of implantation was investigated for different doses
and energies of implantation. The H+ ion-implantation range of doses
and energies was 3×1014 cm-2 - 3×1016 cm-2 and 0.75 MeV–2 MeV, respectively. Furthermore, a two-beam
cross-modulation PCR technique was introduced to perform the same type of
measurements inside and outside the implanted area. Comparison between
contrasts from single- and double-beam methods showed significantly higher
degree of sensitivity for the two-beam PCR technique. 相似文献
15.
G. Durry N. Amarouche L. Joly X. Liu B. Parvitte V. Zéninari 《Applied physics. B, Lasers and optics》2008,90(3-4):573-580
The 2.7 μm spectral range is highly suitable for the in situ monitoring of atmospheric H2O using compact balloonborne laser diode spectrometers. Water vapour spectroscopic parameters of the 202
101 and the 413
414 transitions of the ν3 band are revisited in this spectral region using a new distributed-feedback InGaAsSb laser diode emitting at 2.63 μm. Accurate
line strengths are provided which are well adapted for the in situ probing of the middle atmosphere. Our measurements are
thoroughly compared to an existing molecular database, laboratory measurements and ab-initio calculations. A laser hygrometer
was developed for operation from small stratospheric balloons using this new laser diode technology, with emission at 2.6 μm.
The realized sensor is described and results from a recent test-flight are reported.
PACS 07.57.Ty; 92.60 Jq 相似文献
16.
X. Lu Q. Yang C. Xiao A. Hirose 《Applied Physics A: Materials Science & Processing》2006,82(2):293-296
Diamond nanocone, graphitic nanocone, and mixed diamond and graphitic nanocone films have been synthesized through plasma
enhanced hot filament chemical vapor deposition (HFCVD). The field emission properties of these films have been experimentally
investigated. The studies have revealed that all three kinds of nanocone films have excellent field electron emission (FEE)
properties including low turn-on electric field and large emission current at low electric field. Compared with the diamond
nanocone films (emission current of 86 μA at 26 V/μm with the turn-on field of 10 V/μm), the graphitic nanocone films exhibit
higher FEE current of 1.8×102 μA at 13 V/μm and a lower turn-on filed of 4 V/μm. The mixed diamond and graphitic nanocone films have been found to posses
FEE properties similar to graphitic nanocone films (emission current of 1.7×102 μA at 20 V/μm with the turn-on field of 5 V/μm), but have much better FEE stability than the graphitic nanocone films.
PACS 81.07.Bc; 81.05.Uw; 79.70.+q 相似文献
17.
D. J. Breed J. M. Robertson H. A. Algra B. A. H. van Bakel W. de Geus J. P. H. Heynen 《Applied Physics A: Materials Science & Processing》1981,24(2):163-167
Two types of films for small bubbles have been grown without making use of the rare earth ions which are the cause of increased
damping of the Bloch wall motion in the usual small bubble film compositions. Firstly, Bi-containing films were grown on (111)
orientated GGG for 1 μm bubbles and secondly, Mn3+-containing films were grown under compression on (100) orientated GGG substrates for 0.4 μm bubbles. The damping constants
in these films have been obtained by measuring the FMR line width. The correlation between the damping of the FMR and of the
Bloch wall motion is determined in films with bubble diameters of, 2 to 4 μm. The damping constants are a factor 10 to 100
smaller than in the existing device films for small bubbles. 相似文献
18.
N. Koteeswara Reddy K. Ramesh R. Ganesan K.T. Ramakrishna Reddy K.R. Gunasekhar E.S.R. Gopal 《Applied Physics A: Materials Science & Processing》2006,83(1):133-138
Tin sulphide films were grown at different substrate temperatures by a thermal co-evaporation technique. The crystallinity of the films was evaluated from X-ray diffraction studies. Single-phase SnS films showed a strong (040) orientation with an orthorhombic crystal structure and a grain size of 0.12 μm. The films showed an electrical resistivity of 6.1 Ω cm with an activation energy of 0.26 eV. These films exhibited an optical band gap of 1.37 eV and had a high optical absorption coefficient (>104 cm-1) above the band-gap energy. The results obtained were analysed to evaluate the potentiality of the co-evaporated SnS films as an absorber layer in solar photovoltaic devices. PACS 78.40.Fy; 68.60.-p; 61.10.Nz; 68.55.-a; 78.66.-w 相似文献
19.
D. Richter D.G. Lancaster R.F. Curl W. Neu F.K. Tittel 《Applied physics. B, Lasers and optics》1998,67(3):347-350
3 (PPLN) crystal pumped by two single-frequency diode lasers. A maximum DFG power of 1.6 μW at 3.6 μm was generated with a pump
power of 61.4 mW at 832 nm and a signal power of 41.5 mW at 1083 nm incident on a 19-mm-long PPLN crystal, which corresponds
to a conversion efficiency of 335 μW W-2 cm-1.
Received: 16 June 1998 相似文献
20.
N. K. Leite J. G. Santos R. F. Souza G. M. Cabianchi F. O. Xavier B. M. Gomes L. B. Silveira A. C. Oliveira A. F.R. Rodriguez P. C. Morais 《The European physical journal. Special topics》2008,153(1):45-48
In this study we demonstrate the usefulness of the
Photoacoustic Spectroscopy (PAS) in the investigation of water collected
from a natural site located within the Amazon region, Brazil, during the wet
to dry seasons transition (May/2006). The water samples were collected from
different stages along a hydrologic pathway including precipitation water
(Prec), groundwater (GW), through flow water (TF), overland flow water (OF),
and stream flow water (SW). The observed photoacoustic spectral features, in
the 0.3 to 1.0 μm wavelength region, fall within three distinct bands
(C, S, and L). We found band-C, band-S and band-L occurring in the spectral
range of 0.30 to 0.40 μm, 0.40 to 0.45 μm and 0.45 to 1.0 μm
regions, respectively. The photoacoustic features shift peak positions and
change intensities for all samples investigated, thus supporting the
proposal of PAS as a useful technique to investigate water samples from
natural environments. 相似文献