Library

X
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
    Electronic Resource
    Electronic Resource
    Modulations in incommensurate (Ca1–xSrx)2MgSi2O7 single crystals (1998)
    Springer
    Physics and chemistry of minerals 26 (1998), S. 128-134 
    Details
    ISSN: 1432-2021
    Keywords: Key words strontium åkermanite ; single crystals ; modulated structure ; electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract  Single crystals of (Ca1–xSrx)2MgSi2O7 slightly doped with 1000 ppm Mn2+ and with x ranging from 0.04 to 0.32 were grown from the melt in a mirror furnace applying the Czochalski technique. Transmission electron microscopy (TEM) revealed incommensurately modulated structures at room-temperature for all compositions in accordance with earlier studies by electron paramagnetic resonance (EPR). Electron diffraction patterns clearly show satellite reflections typical for two-dimensional modulation, and their successive destabilization with increasing Sr content. The modulation is of tartan-like appearance. Beyond a Sr/(Sr+Ca) ratio of about 0.32 the synthesis of stable solid solution åkermanite type crystals was proved not to be feasible, indicating the existence of a miscibility gap in the Sr åkermanite system. As presumed from the diffuse scattering around the satellite reflections, and suggested more conclusively by crystallographic processing of high resolution EM images the Sr ions incorporated into the incommensurate crystal phase are distributed in an ordered fashion and are partly adapted to the displacive modulation of the pure åkermanite. This means, occupational modulation even makes a contribution to the overall modulation characteristics in (Ca1–xSrx)2 MgSi2O7.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002690050169
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The electron microscope characterization of the fine structure of nylon 6: I. The supermolecular structure in melt-cast, isotropic bulk material (1986)
    Springer
    Colloid & polymer science 264 (1986), S. 649-658 
    Details
    ISSN: 1435-1536
    Keywords: Nylon 6 ; electron microscopy ; staining ; spherulites ; lamellar crystals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The application of phosphotungstic acid (PTA) as a staining agent with appropriate hardening procedures and accurate ultra-thin sectioning has enabled the direct transmission electron microscope (TEM) investigation to be carried out on the lamellar fine structure of bulk nylon 6. Details of the organization of the crystal lamellae within spherulites and other morphological structures, their shape and, especially, their dimensions were revealed and the mean structural long period was determined. Interspherulitic regions without any indication of crystalline ordering could be observed in samples which were rapidly cooled from the melt. The investigations on bulk material were completed by observations on solution-grown thin films. Optical diffraction (OD) was used for evaluating the electron micrographs; the results were compared with the data from small angle X-ray scattering (SAXS).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01469525
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The electron microscope characterization of the fine structure of nylon 6: II. On the rearrangement of the structure during cold-drawing (1986)
    Springer
    Colloid & polymer science 264 (1986), S. 668-675 
    Details
    ISSN: 1435-1536
    Keywords: Nylon 6 ; cold-drawing ; electron microscopy ; staining ; transverse structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The transmission electron microscope (TEM) visualization of the supermolecular structure of cold-drawn, oriented nylon 6 bulk material (bristles) by stained ultra-thin sections is reported. For evaluating the electron micrographs optical diffraction (OD) has been applied in comparison with small angle X-ray scattering (SAXS). The deformation of the spherulites was followed by polarization microscopy. In addition, investigations were carried out on commercial nylon 6 fibres. As the main result a transverse structure was revealed within the drawn samples at draw ratios between λ=4 and 4.5, consisting of mosaic crystals which show some lateral alignment. The structure is described by a modified layer lattice model. While the long period may increase slightly during drawing, the crystallite thickness remains almost constant. Fibres with λ=3.4 show a similarly oriented structure though the lateral alignment of the crystals is not so pronounced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01469527
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...