ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The understanding of the phenomena of ferroelectricity requires profound knowledge of the ferroelectric domain structure. In this paper we report on the progress of studying ferroelectric domains and domain walls with scanning force microscopy (SFM). Domains and domain walls of ferroelectric crystals of guanidinium aluminum sulfate hexahydrate (GASH) are imaged with SFM. Two sets of complementary results are obtained depending on the operation mode of the instrument. In the non-contact imaging mode (attractive force regime), domain walls are imaged. In the contact imaging mode (repulsive force regime) in addition to the domain wall structure, information about the polarity of the domains is obtained. In these latter images, the opposing contrast of the ferroelectric positive and negative domains is superimposed on the GASH cleavage structure. The imaging mechanism of the contact and noncontact modes are discussed. Corroborating scanning electron microscopy images are presented as well.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2015-10-24
    Description: We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth’s magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz 1/2 . The width of superconducting strip lines is restricted to less than 6 μ m in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 μ T amplitude without the need for recalibration.
    Print ISSN: 0034-6748
    Electronic ISSN: 1089-7623
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2016-04-30
    Description: A new ultra-low temperature experiment including a superconducting vector magnet has been developed for soft x-ray absorption spectroscopy experiments at third generation synchrotron light sources. The sample is cooled below 50 mK by a cryogen free 3 He- 4 He dilution refrigerator. At the same time, magnetic fields of up to ±7 T in the horizontal direction and ±0.5 T in the vertical direction can be applied by a superconducting vector magnet. The setup allows to study ex situ and in situ prepared samples, offered by an attached UHV preparation chamber with load lock. The transfer of the prepared samples between the preparation section and the dilution refrigerator is carried out under cryogenic temperatures. First commissioning studies have been carried out at the Variable Polarization XUV Beamline P04 at PETRA III and the influence of the incident photon beam to the sample temperature has been studied.
    Print ISSN: 0034-6748
    Electronic ISSN: 1089-7623
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The surface, structural, and optical properties of InAs/InGaSb/AlSb mid-infrared lasers grown by molecular beam epitaxy have been systematically studied, respectively, by Nomarski differential interference contrast, high-resolution x-ray diffraction, and variable-temperature photoluminescence. It is found that the optimum growth temperature is between 400 and 450 °C, based on the calibrated transmission thermometry. In addition, the impact of interfacial bond type and Sb sources has been investigated. A 5.91 μm laser, grown with the optimal growth parameters, exhibits a maximum cw operating temperature of 210 K. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Optical and electrical measurements were carried out on annealed CuIn(Ga)Se2 (CIGS) thin films with Ga content of 10%. Annealing of as-grown In-rich CIGS in air/oxygen at 400 °C changes the photoluminescence spectrum to a spectrum which is usually obtained from as-grown Cu-rich CIGS. The annealing step reduces the donor density and the high compensation. This effect allows the investigation of the defect levels of In-rich CIGS which is not possible in as-grown layers due to the dominating fluctuating potentials. The activation energies for the donors and acceptors in In-rich CIGS were found to be 10 and 75 meV, respectively. The densities are in the order of 1018 cm−3 each, with a compensation ratio of 0.99.© 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 4966-4973 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present an improved quantitative mobility spectrum analysis (i-QMSA) procedure for determining free electron and hole densities and mobilities from magnetic-field-dependent Hall and resistivity measurements on bulk or layered semiconductor samples. The i-QMSA technique is based on a fundamentally new approach, which optimizes the fit to the conductivity tensor components and their slopes by making those adjustments in the mobility spectra that result in the greatest error reduction. Empirical procedures for manipulating the mobility spectra are also introduced, with the dual purpose of reducing the error of the fit and simplifying the shape of the spectra to minimize the presence of unphysical artifacts. A fully automated computer implementation of the improved QMSA is applied to representative synthetic and real data sets involving various semiconductor material systems. These results show that, as compared with previous approaches, the presented algorithm maximizes the information that may be extracted from a given data set, and is suitable for use as a standard tool in the characterization of semiconductor material and device transport properties. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 1882-1887 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: We consider the applicability of the established rf readout technique, which allows to obtain the supercurrent-phase relation of a Josephson element from impedance measurements in the phase-biased regime. In experiments on Nb-based single and double tunnel junctions, we demonstrate that this method holds even if the Josephson coupling energy is smaller than the thermal energy. Compared with conventional current–voltage measurements, we evaluate the rf technique to be favorable in particular for investigations of small supercurrents in low-capacitance Josephson elements. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 71 (2000), S. 1862-1868 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new instrumentation system for measuring wide frequency band complex permittivity (1 MHz–2 GHz) during the microwave curing process has been developed using an original system coupled with coaxial discontinuity. The instrumentation operates through the automatic commutation of the wide frequency band cell on a power supply or a probe supply. This system allows the use of different heating frequencies (215 MHz, 434 MHz, or 2.45 GHz) with the same cell. This instrumentation has been used to study microwave curing compared with conventional heating, but it can also be applied to the use of microwaves in chemical processes or to study the biological effects of microwaves. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In contrast to the widely accepted model of ion cooling, which is supposed to fully explain the gas mixing effect, we recently presented an alternative model of self-enhanced sputtering of wall material. In order to prove our model further, we numerically simulated different plasma parameters in the vicinity of plasma limiting edges of the discharge chamber (walls) via particle in cell and Monte Carlo methods. Both experimental investigations and simulations give clear evidence that the optimization of an electron cyclotron resonance ion source with respect to the high charge state production is sensitively influenced by the contamination of the plasma with heavy atoms sputtered off the walls. Any optimization of the charge state distribution in physical terms means nothing else than balancing the ratio of hot and cold electrons. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A technique for simultaneous energy distribution and ion fraction measurements using a linear time-of-flight analyzer with a floatable drift tube is described. Analytical expressions for the relative collection efficiency and viewing region of the apparatus are developed as functions of the analyzed particle reduced energy and dimensionless apparatus parameters. The method was applied to studies of large-angle scattering of singly charged oxygen ions incident on Au(110), and carried out at the Oak Ridge National Laboratory's Multicharged Ion Research Facility. Energy distributions of the scattered projectiles and the negative ion fraction are presented as a function of scattered projectile energy. As a by-product of the measurements, the relative ion detection efficiency of the particle detector was reconstructed as a function of ion impact energy on the detector. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...