Theoretical and Experimental Study of the Diffraction Contrast on Magnetic Domain Walls

1982 ◽  
Vol 37 (5) ◽  
pp. 419-426 ◽  
Author(s):  
M. Polcarová ◽  
J. Brádler

Dynamical theory of the X-ray diffraction on a crystal containing misfit boundary was applied to the interpretation of the contrast observed in X-ray topographs on 90° magnetic domain walls in single crystals of an Fe-Si alloy. The integrated intensities were computed for several cases corresponding to the actual conditions of experiments. Good agreement of theoretical and experi­mental results was obtained.

2016 ◽  
Vol 35 (6) ◽  
pp. 551-557 ◽  
Author(s):  
Omid Amiri ◽  
Mohammad Reza Mozdianfar ◽  
Mahmoud Vahid ◽  
Masoud Salavati-Niasari ◽  
Sousan Gholamrezaei

AbstractBiFeO3 nanopowders with new morphology have been synthesized by different methods. X-ray diffraction analysis, scanning electron microscopy, Fourier transform infrared and vibrating sample magnetometer were carried out at room temperature to study the structural and magnetic properties of as-synthesized products. VSM was utilized to measure the size-dependent magnetic behaviors of the as-prepared nanoparticles. Results show that the method has strong effect on the purity of the products. BFO synthesized by third method was pure. Crystallite size has a great effect on the magnetic properties. According to these results the nanoparticle diameter is smaller than the critical single-domain diameter, avoiding the configuration of magnetic domain walls decreases the magnetization. Even though the diameter of particle becomes even smaller, the thermal stability of the magnetization orientation decreases.


1993 ◽  
Vol 310 ◽  
Author(s):  
S. Wang ◽  
M. Dudley ◽  
L.K. Cheng ◽  
J.D. Bierlein ◽  
W. Bindloss

AbstractThe application of synchrotron white beam X-ray topography to the study of ferroelectric domain structures in hydrothermally grown potassium titanyl phosphate (KTiOPO4: KTP) single crystals is reported. The domain walls can be exclusively imaged on topographs with selected diffraction vectors and X-ray wavelengths, while images of other defects, such as dislocations, inclusions and surface scratches, can be simultaneously made very diffuse. The topographic images correspond well with electrostatic toning images. X-ray topography readily reveals the three dimensional shapes of the domain walls. There are two contributions to domain wall contrast: one is fringe-like which can be interpreted in terms of the dynamical theory of X-ray diffraction, and the other is diffuse strain contrast arising from long range strain associated with the wall. These two contributions can be observed simultaneously or separately depending on the diffraction conditions. The long range strain is thought to be associated with the curvature of the domain walls. It appears that the main components of the displacement field associated with this strain are directed approximately perpendicular to the domain wall.


1977 ◽  
Vol 36 (4) ◽  
pp. 763-776 ◽  
Author(s):  
W. J. Boettinger ◽  
H. E. Burdette ◽  
M. Kuriyama

2019 ◽  
Vol 75 (3) ◽  
pp. 483-488 ◽  
Author(s):  
Kouhei Okitsu ◽  
Yasuhiko Imai ◽  
Yoshitaka Yoda

Non-coplanar 18-beam X-ray pinhole topographs for a silicon crystal were computer simulated by fast Fourier transforming the X-ray rocking amplitudes that were obtained by solving the n-beam (n = 18) Ewald–Laue dynamical theory (E-L&FFT method). They were in good agreement with the experimentally obtained images captured using synchrotron X-rays. From this result and further consideration based on it, it has been clarified that the X-ray diffraction intensities when n X-ray waves are simultaneously strong in the crystal can be computed for any n by using the E-L&FFT method.


1981 ◽  
Vol 59 (1) ◽  
pp. 38-44 ◽  
Author(s):  
R. H. Marchessault ◽  
Suzanne Coulombe ◽  
Hiromichi Morikawa ◽  
Keizo Okamura ◽  
J. F. Revol

The solid state properties of poly-β-hydroxybutyrate (PHB) were investigated for samples with degrees of polymerization [Formula: see text] from 4 to 994. The observed melting points ranged from 47 °C to 180 °C. Electron diffractograms on carefully prepared single crystals of a high molecular weight sample provided data which confirmed the reported a and b parameters from X-ray fiber diffraction and provided clear justification for the P212121 space group. The observed intensities in the electron diffractogram, corresponding to (hk0) reflections, were compared with the predicted intensities for two proposed structures in the literature. The observed and calculated structure factors for both structures were in good agreement. Small angle X-ray diffraction of the meridional maximum for annealed "cold drawn" and "hot drawn" fibers showed a distinctly different dependence on temperature than the maximum for stacks of lamellar single crystals. For oligomers a long spacing was observed which was about twice the length of the sample [Formula: see text] multiplied by the crystalline advance per monomer.


Sign in / Sign up

Export Citation Format

Share Document