Jump to Content
View Cart
Top 20 Most Read Articles
June 2011
The 20 articles with the most full-text downloads during the month, in descending order.
 |
WSXM: A software for scanning probe microscopy and a tool for nanotechnology Rev. Sci. Instrum. 78, 013705 (2007); http://dx.doi.org/10.1063/1.2432410 (8 pages) Online Publication Date: 31 January 2007
Full Text:
Read Online (HTML)
|
Download PDF
|
|||
|
Show Abstract
In this work we briefly describe the most relevant features of WSXM, a freeware scanning probe microscopy software based on MS-Windows. The article is structured in three different sections: The introduction is a perspective on the importance of software on scanning probe microscopy. The second section is devoted to describe the general structure of the application; in this section the capabilities of WSXM to read third party files are stressed. Finally, a detailed discussion of some relevant procedures of the software is carried out.
|
||||
|
Show PACS
|
||||
|
|
Rev. Sci. Instrum. 82, 043710 (2011); http://dx.doi.org/10.1063/1.3584935 (5 pages) Online Publication Date: 28 April 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
For manufacturing at the nanometre scale a method for rapid and accurate measurement of the resultant functional devices is required. Although atomic force microscopy (AFM) has the requisite spatial resolution, it is severely limited in scan speed, the resolution and repeatability of vertical and lateral measurements being degraded when speed is increased. Here we present a new approach to AFM that makes a direct and feedback-independent measurement of surface height using a laser interferometer focused onto the back of the AFM tip. Combining this direct height measurement with a passive, feedback-free method for maintaining tip-sample contact removes the constraint on scan speed that comes from the bandwidth of the z-feedback loop. Conventional laser reflection detection is used for feedback control, which now plays the role of minimising tip-sample forces, rather than producing the sample topography. Using the system in conjunction with a rapid scanner, true height images are obtained with areas up to (36 × 36) μm2 at 1 image/second, suitable for in-line applications. |
|||
|
Show PACS
|
|||
|
|
Antenna-based ultrahigh vacuum microwave frequency scanning tunneling microscopy system Rev. Sci. Instrum. 82, 053710 (2011); http://dx.doi.org/10.1063/1.3592992 (7 pages) Online Publication Date: 26 May 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
The instrumental synthesis of high resolution scanning tunneling microscopy (STM) with the ability to measure differential capacitance with atomic scale resolution is highly desirable for fundamental metrology and for the study of novel physical characteristics. Microwave frequency radiation directed at the tip-sample junction in an STM system allows for such high-resolution differential capacitance information. This ability is particularly critical in ultrahigh vacuum environments, where the additional parameter space afforded by including a capacitance measurement would prove powerful. Here we describe the modifications made to a commercial scanning tunneling microscope to allow for broad microwave frequency alternating current scanning tunneling microscopy (ACSTM) in ultrahigh vacuum conditions using a relatively simple loop antenna and microwave difference frequency detection. The advantages of our system are twofold. First, the use of a removable antenna on a commercial STM prevents interference with other UHV processes while providing a simple method to retrofit any commercial UHV-STM with UHV-ACSTM capability. Second, mounting the microwave antenna on a translator allows for specific tuning of the system to replicate experimental conditions between samples, which is particularly critical in sensitive systems like organic thin films or single molecules where small changes in incident power can affect the results. Our innovation therefore provides a valuable approach to give nearly any commercial STM, be it an ambient or UHV system, the capability to measure atomic-scale microwave studies such as differential capacitance or even single molecule microwave response, and it ensures that experimental ACSTM conditions can be held constant between different samples. |
|||
|
Show PACS
|
|||
|
|
Rev. Sci. Instrum. 82, 033109 (2011); http://dx.doi.org/10.1063/1.3563723 (8 pages) Online Publication Date: 24 March 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
A velocity map imaging/ion time-of-flight spectrometer designed specifically for pump–probe experiments combining synchrotron and laser radiations is described. The in-house built delay line detector can be used in two modes: the high spatial resolution mode and the coincidence mode. In the high spatial resolution mode a kinetic energy resolution of 6% has been achieved. The coincidence mode can be used to improve signal-to-noise ratio for the pump–probe experiments either by using a gate to count electrons only when the laser is present or by recording coincidences with the ion formed in the ionization process.
|
|||
|
Show PACS
|
|||
|
|
Voltage preamplifier for extensional quartz sensors used in scanning force microscopy Rev. Sci. Instrum. 82, 063701 (2011); http://dx.doi.org/10.1063/1.3594103 (9 pages) Online Publication Date: 2 June 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Extensional-mode quartz resonators are being increasingly used as force sensors in dynamic scanning force microscopy or atomic force microscopy (AFM). We propose a voltage preamplifier in order to amplify the charge induced on quartz electrodes. The proposed solution has some advantages over the typically used current-to-voltage converters. First, the gain does not depend on the inner parameters of the quartz resonator, which are usually unknown for the specific resonator and may even vary during the measurement. Second, with such an amplifier a better signal-to-noise ratio can be achieved. Finally, we present AFM images of the Si(111) and the SiO2 surfaces obtained by the voltage preamplifier with simultaneously recorded tunneling current. |
|||
|
Show PACS
|
|||
|
|
An efficient setup for femtosecond stimulated Raman spectroscopy Rev. Sci. Instrum. 82, 063102 (2011); http://dx.doi.org/10.1063/1.3596453 (9 pages) Online Publication Date: 2 June 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
We present an efficient and robust setup for femtosecond stimulated Raman (FSR) spectroscopy with 60 fs and 10 cm−1 resolution. Raman pulses of 0.5–5 ps are tunable between 450–750 nm with energies1–10 μJ. Experimental features of the setup, signal processing, and data treatment are discussed in detail to be readily reproduced in other labs. The setup is tested by measuring FSR spectra of stilbene in solution. |
|||
|
Show PACS
|
|||
|
|
Ultra-broadband infrared pump-probe spectroscopy using synchrotron radiation and a tuneable pump Rev. Sci. Instrum. 82, 063101 (2011); http://dx.doi.org/10.1063/1.3592332 (9 pages) Online Publication Date: 1 June 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Synchrotron infrared sources have become popular mainly because of their excellent broadband brilliance, which enables spectroscopically resolved spatial-mapping of stationary objects at the diffraction limit. In this article we focus on an often-neglected further advantage of such sources – their unique time-structure – to bring such broadband spectroscopy to the time domain, for studying dynamic phenomenon down to the 100 ps limit. We describe the ultra-broadband (12.5 to 1.1 μm) Fourier transform pump-probe setup, for condensed matter transmission- and reflection-spectroscopy, installed at the X01DC infrared beam-line of the Swiss Light Source (SLS). The optical pump consists of a widely tuneable 100 ps 1 kHz laser system, covering 94% of the 16 to 1.1 μm range. A thorough description of the system is given, including (i) the vector-modulator providing purely electronic tuning of the pump-probe overlap up to 1 ms with sub-ps time resolution, (ii) the 500 MHz data acquisition system interfaced with the experimental physics and industrial control system (EPICS) based SLS control system for consecutive pulse sampling, and (iii) the step-scan time-slice Fourier transform scheme for simultaneous recording of the dual-channel pumped, un-pumped, and difference spectra. The typical signal/noise ratio of a single interferogram in a 100 ps time slice is 300 (measured during one single 140 s TopUp period). This signal/noise ratio is comparable to that of existing gated Globar pump-probe Fourier transform spectroscopy, but brings up to four orders of magnitude better time resolution. To showcase the utility of broadband pump-probe spectroscopy, we investigate a Ge-on-Si material system similar to that in which optically pumped direct-gap lasing was recently reported. We show that the mid-infrared reflection-spectra can be used to determine the optically injected carrier density, while the mid- and near-infrared transmission-spectra can be used to separate the strong pump-induced absorption and inversion processes present at the direct-gap energy. |
|||
|
Show PACS
|
|||
|
|
Invited Review Article: A 10 mK scanning probe microscopy facility Rev. Sci. Instrum. 81, 121101 (2010); http://dx.doi.org/10.1063/1.3520482 (33 pages) Online Publication Date: 29 December 2010
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
We describe the design, development and performance of a scanning probe microscopy (SPM) facility operating at a base temperature of 10 mK in magnetic fields up to 15 T. The microscope is cooled by a custom designed, fully ultra-high vacuum (UHV) compatible dilution refrigerator (DR) and is capable of in situ tip and sample exchange. Subpicometer stability at the tip-sample junction is achieved through three independent vibration isolation stages and careful design of the dilution refrigerator. The system can be connected to, or disconnected from, a network of interconnected auxiliary UHV chambers, which include growth chambers for metal and semiconductor samples, a field-ion microscope for tip characterization, and a fully independent additional quick access low temperature scanning tunneling microscope (STM) and atomic force microscope (AFM) system. To characterize the system, we present the cooling performance of the DR, vibrational, tunneling current, and tip-sample displacement noise measurements. In addition, we show the spectral resolution capabilities with tunneling spectroscopy results obtained on an epitaxial graphene sample resolving the quantum Landau levels in a magnetic field, including the sublevels corresponding to the lifting of the electron spin and valley degeneracies.
|
|||
|
Show PACS
|
|||
|
|
Rev. Sci. Instrum. 78, 031101 (2007); http://dx.doi.org/10.1063/1.2709758 (20 pages) Online Publication Date: 30 March 2007
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
The technique of atom probe tomography (APT) is reviewed with an emphasis on illustrating what is possible with the technique both now and in the future. APT delivers the highest spatial resolution (sub-0.3-nm) three-dimensional compositional information of any microscopy technique. Recently, APT has changed dramatically with new hardware configurations that greatly simplify the technique and improve the rate of data acquisition. In addition, new methods have been developed to fabricate suitable specimens from new classes of materials. Applications of APT have expanded from structural metals and alloys to thin multilayer films on planar substrates, dielectric films, semiconducting structures and devices, and ceramic materials. This trend toward a broader range of materials and applications is likely to continue.
|
|||
|
Show PACS
|
|||
|
|
Thermal conductivity measurement from 30 to 750 K: the 3ω method Rev. Sci. Instrum. 61, 802 (1990); http://dx.doi.org/10.1063/1.1141498 (7 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
An ac technique for measuring the thermal conductivity of dielectric solids between 30 and 750 K is described. This technique, the 3ω method, can be applied to bulk amorphous solids and crystals as well as amorphous films tens of microns thick. Errors from black‐body radiation are calculated to be less than 2% even at 1000 K. Data for a‐SiO2, Pyrex 7740, and Pyroceram 9606 are compared to results obtained by conventional techniques. |
|||
|
Show PACS
|
|||
|
|
Femtosecond pulse shaping using spatial light modulators Rev. Sci. Instrum. 71, 1929 (2000); http://dx.doi.org/10.1063/1.1150614 (32 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
We review the field of femtosecond pulse shaping, in which Fourier synthesis methods are used to generate nearly arbitrarily shaped ultrafast optical wave forms according to user specification. An emphasis is placed on programmable pulse shaping methods based on the use of spatial light modulators. After outlining the fundamental principles of pulse shaping, we then present a detailed discussion of pulse shaping using several different types of spatial light modulators. Finally, new research directions in pulse shaping, and applications of pulse shaping to optical communications, biomedical optical imaging, high power laser amplifiers, quantum control, and laser-electron beam interactions are reviewed. © 2000 American Institute of Physics. |
|||
|
Show PACS
|
|||
|
|
In situ nanomechanical testing in focused ion beam and scanning electron microscopes Rev. Sci. Instrum. 82, 063901 (2011); http://dx.doi.org/10.1063/1.3595423 (12 pages) Online Publication Date: 3 June 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
|||||||||||
|
Show Abstract
The recent interest in size-dependent deformation of micro- and nanoscale materials has paralleled both technological miniaturization and advancements in imaging and small-scale mechanical testing methods. Here we describe a quantitative in situ nanomechanical testing approach adapted to a dual-beam focused ion beam and scanning electron microscope. A transducer based on a three-plate capacitor system is used for high-fidelity force and displacement measurements. Specimen manipulation, transfer, and alignment are performed using a manipulator, independently controlled positioners, and the focused ion beam. Gripping of specimens is achieved using electron-beam assisted Pt-organic deposition. Local strain measurements are obtained using digital image correlation of electron images taken during testing. Examples showing results for tensile testing of single-crystalline metallic nanowires and compression of nanoporous Au pillars will be presented in the context of size effects on mechanical behavior and highlight some of the challenges of conducting nanomechanical testing in vacuum environments. |
||||||||||||
|
Show PACS
|
||||||||||||
|
|
Compact fiber-coupled terahertz spectroscopy system pumped at 800 nm wavelength Rev. Sci. Instrum. 82, 053102 (2011); http://dx.doi.org/10.1063/1.3587070 (7 pages) Online Publication Date: 10 May 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Photonic terahertz (THz) technology using femtosecond (fs) lasers has a great potential in a wide range of applications, such as non-destructive testing of objects or spectroscopic identification of chemical substances. For industrial purposes, a THz system has to be compact and easily implementable into the particular application. Therefore, fiber-coupled THz systems are the key to a widespread use of THz technology. In order to have flexible THz emitters and detectors near infrared fs light pulses have to be sent through optical fibers of considerable length. As a consequence, the fiber's dispersion has to be compensated for and nonlinear effects in the fiber have to be minimized. A fiber-based THz time-domain spectroscopy system of high stability, flexibility, and portability is presented here.
|
|||
|
Show PACS
|
|||
|
|
Photoacoustic imaging in biomedicine Rev. Sci. Instrum. 77, 041101 (2006); http://dx.doi.org/10.1063/1.2195024 (22 pages) Online Publication Date: 17 April 2006
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Photoacoustic imaging (also called optoacoustic or thermoacoustic imaging) has the potential to image animal or human organs, such as the breast and the brain, with simultaneous high contrast and high spatial resolution. This article provides an overview of the rapidly expanding field of photoacoustic imaging for biomedical applications. Imaging techniques, including depth profiling in layered media, scanning tomography with focused ultrasonic transducers, image forming with an acoustic lens, and computed tomography with unfocused transducers, are introduced. Special emphasis is placed on computed tomography, including reconstruction algorithms, spatial resolution, and related recent experiments. Promising biomedical applications are discussed throughout the text, including (1) tomographic imaging of the skin and other superficial organs by laser-induced photoacoustic microscopy, which offers the critical advantages, over current high-resolution optical imaging modalities, of deeper imaging depth and higher absorption contrasts, (2) breast cancer detection by near-infrared light or radio-frequency–wave-induced photoacoustic imaging, which has important potential for early detection, and (3) small animal imaging by laser-induced photoacoustic imaging, which measures unique optical absorption contrasts related to important biochemical information and provides better resolution in deep tissues than optical imaging.
|
|||
|
Show PACS
|
|||
|
|
Time‐of‐Flight Mass Spectrometer with Improved Resolution Rev. Sci. Instrum. 26, 1150 (1955); http://dx.doi.org/10.1063/1.1715212 (8 pages) Online Publication Date: 29 December 2004
Full Text:
|
Download PDF
|
||
|
Show Abstract
A new type of ion gun is described which greatly improves the resolution of a nonmagnetic time‐of‐flight mass spectrometer. The focusing action of this gun is discussed and analyzed mathematically. The validity of the analysis and the practicability of the gun are demonstrated by the spectra obtained. The spectrometer is capable of measuring the relative abundance of adjacent masses well beyond 100 amu. |
|||
|
|
Modulated 3D cross-correlation light scattering: Improving turbid sample characterization Rev. Sci. Instrum. 81, 123107 (2010); http://dx.doi.org/10.1063/1.3518961 (7 pages) Online Publication Date: 30 December 2010
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Accurate characterization using static light scattering (SLS) and dynamic light scattering (DLS) methods mandates the measurement and analysis of singly scattered light. In turbid samples, the suppression of multiple scattering is therefore required to obtain meaningful results. One powerful technique for achieving this, known as 3D cross-correlation, uses two simultaneous light scattering experiments performed at the same scattering vector on the same sample volume in order to extract only the single scattering information common to both. Here we present a significant improvement to this method in which the two scattering experiments are temporally separated by modulating the incident laser beams and gating the detector outputs at frequencies exceeding the timescale of the system dynamics. This robust modulation scheme eliminates cross-talk between the two beam-detector pairs and leads to a fourfold improvement in the cross-correlation intercept. We measure the dynamic and angular-dependent scattering intensity of turbid colloidal suspensions and exploit the improved signal quality of the modulated 3D cross-correlation DLS and SLS techniques.
|
|||
|
Show PACS
|
|||
|
|
Surface magneto-optic Kerr effect Rev. Sci. Instrum. 71, 1243 (2000); http://dx.doi.org/10.1063/1.1150496 (13 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
The surface magneto-optic Kerr effect (SMOKE) has significantly impacted research on magnetic thin films. This is due to its sensitivity, local probing nature, and experimental simplicity. The polar and longitudinal Kerr effects are characterized by a complex rotation of the plane of polarization of linearly polarized incident light upon reflection from the surface of a ferromagnetic material. The rotation is directly related to the magnetization of the material within the probing region of the light. Light penetrates into metals >20 nm deep, but the SMOKE technique derives its surface sensitivity from the limited thickness of the deposited magnetic film, which can be as thin as one atomic layer. Basic principles, experimental arrangements, and applications of SMOKE are reviewed in order to acquaint the nonspecialist with the technique and place it into perspective. © 2000 American Institute of Physics. |
|||
|
Show PACS
|
|||
|
|
Rev. Sci. Instrum. 82, 053906 (2011); http://dx.doi.org/10.1063/1.3590745 (8 pages) Online Publication Date: 26 May 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
A miniature opposed-anvil high-pressure cell has been developed for magnetic measurement in a commercial superconducting quantum interference device magnetometer. Non-magnetic anvils made of composite ceramic material were used to generate high-pressure with a Cu-Be gasket. We have examined anvils with different culet sizes (1.8, 1.6, 1.4, 1.2, 1.0, 0.8, and 0.6 mm). The pressure generated at low temperature was determined by the pressure dependence of the superconducting transition of lead (Pb). The maximum pressure Pmax depends on the culet size of the anvil: the values of Pmax are 2.4 and 7.6 GPa for 1.8 and 0.6 mm culet anvils, respectively. We revealed that the composite ceramic anvil has potential to generate high-pressure above 5 GPa. The background magnetization of the Cu-Be gasket is generally two orders of magnitude smaller than the Ni-Cr-Al gasket for the indenter cell. The present cell can be used not only with ferromagnetic and superconducting materials with large magnetization but also with antiferromagnetic compounds with smaller magnetization. The production cost of the present pressure cell is about one tenth of that of a diamond anvil cell. The anvil alignment mechanism is not necessary in the present pressure cell because of the strong fracture toughness (6.5 MPa m1/2) of the composite ceramic anvil. The simplified pressure cell is easy-to-use for researchers who are not familiar with high-pressure technology. Representative results on the magnetization of superconducting MgB2 and antiferromagnet CePd5Al2 are reported.
|
|||
|
Show PACS
|
|||
|
|
Fiber optic probe hydrophone for the study of acoustic cavitation in water Rev. Sci. Instrum. 82, 034904 (2011); http://dx.doi.org/10.1063/1.3557420 (8 pages) Online Publication Date: 15 March 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
|||||||||||
|
Show Abstract
We use focused ultrasound bursts to submit a liquid to mechanical tension. When the pressure in the sound wave reaches a sufficiently low value, vapor bubbles are nucleated in the bulk liquid. According to nucleation theory, increasing the ultrasound frequency increases the cavitation threshold by a calculable amount. To check this, we have built a fiber optic probe hydrophone based on one originally proposed by Staudenraus and Eisenmenger [Ultrasonics 31, 267 (1993)]. We have adapted the pressure calibration and data analysis of this tool to make it appropriate for precise measurements of tension in liquids. We are able to resolve the fractional change in the pressure threshold for cavitation in water that results from a twofold increase in the frequency. This provides a test of nucleation theory in general.
|
||||||||||||
|
Show PACS
|
||||||||||||
|
|
Rev. Sci. Instrum. 82, 053702 (2011); http://dx.doi.org/10.1063/1.3585984 (7 pages) Online Publication Date: 11 May 2011
Full Text:
Read Online (HTML)
|
Download PDF
|
|||
|
Show Abstract
We present the design and the performance of the FAST (Fast Acquisition of SPM Timeseries) module, an add-on instrument that can drive commercial scanning probe microscopes (SPM) at and beyond video rate image frequencies. In the design of this module, we adopted and integrated several technical solutions previously proposed by different groups in order to overcome the problems encountered when driving SPMs at high scanning frequencies. The fast probe motion control and signal acquisition are implemented in a way that is totally transparent to the existing control electronics, allowing the user to switch immediately and seamlessly to the fast scanning mode when imaging in the conventional slow mode. The unit provides a completely non-invasive, fast scanning upgrade to common SPM instruments that are not specifically designed for high speed scanning. To test its performance, we used this module to drive a commercial scanning tunneling microscope (STM) system in a quasi-constant height mode to frame rates of 100 Hz and above, demonstrating extremely stable and high resolution imaging capabilities. The module is extremely versatile and its application is not limited to STM setups but can, in principle, be generalized to any scanning probe instrument.
|
||||
|
Show PACS
|
||||
This Publication
Scitation
Google Scholar
PubMed