Investigations of short range order in amorphous Fe-B alloys

Author(s):  
J. Zweck ◽  
H. Hoffmann

Amorphous metallic alloys exhibit a large variety of physical properties that often differ from their crystalline counterparts of the same composition. Currently, metallic glasses exist which, to name only a few examples, are either very non-abrasive, soft magnetic and magneto optical, hard, flexible, or resistant to corrosion. These properties are of great technical importance and there are many applications that are based on amorphous alloys. Since physical properties are related to the structure of a material, a better knowledge of the ‘structure’ of the amorphous state is of great interest. In this work, we present pair distribution functions determined from electron diffraction results for amorphous Fe-B alloys of different compositions. From the pair distribution functions one can obtain information about near neighbor distances, the range of a short range order (SRO) for different compositions, and of similarities to crystalline counterparts. These findings will also be compared to results obtained with the use of high resolution electron microscopy (HREM).

2017 ◽  
Vol 125 ◽  
pp. 15-26 ◽  
Author(s):  
L.R. Owen ◽  
H.Y. Playford ◽  
H.J. Stone ◽  
M.G. Tucker

Author(s):  
M. Tewes ◽  
J. Zweck ◽  
H. Hoffmann

The importance of amorphous rare-earth/transition-metal (Re-TM) alloys for use as magneto-optic (MO) storage media has been shown first in 1973. First atomic structural data of amorphous Fe2Tb were given in 1974 and compared with those of a crystalline counterpart, which is the well-known Laves phase. Significant differences of short range order (sro) in amorphous and crystalline Fe2Tb have been found. Similiar results were given in 1986 for a composition Fe79Tb21, to be used for MO-recording.In this work we present pair distribution functions (PDF’s) determined from electron diffraction data for amorphous FeTb alloys. It has been shown that Fourier transformation of the experimental observed diffraction intensities gives the original infinite lattice of an investigated (crystalline) specimen multiplied by its selfcorrelation-function. Therefore the PDF approaches zero for r-values greater than the distance ro representing the mean dimension of a crystal.


1993 ◽  
Vol 307 ◽  
Author(s):  
J. P. Quintana

ABSTRACTLocal atomic arrangements in Hg0.80Cd0. 20Te were investigated by measuring the diffuse x-ray scattering at two different energies near the HgLIII absorption edge to yield intensity due only to Hg-Hg, Hg-Te, and Hg-Cd pair interactions. The data were separated into short range order and displacement intensities. Simulation revealed ordered regions with 3:1 Hg-Cd near neighbor configurations. The Hg-Te length is contracted.


2009 ◽  
Vol 24 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Y.M. Chen ◽  
T. Ohkubo ◽  
T. Mukai ◽  
K. Hono

The atomic structure of shear bands in Pd40Ni40P20 bulk metallic glass has been compared to an undeformed matrix phase using pair distribution functions (PDFs) derived from energy filtered nanobeam electron diffraction. Shear bands do not show any characteristic contrast in transmission electron microscopy (TEM) images when specimens are prepared with uniform thickness. PDFs from a shear band exhibit a slight decrease in the first peak, indicating a slight difference in packing density and short range order compared to the undeformed matrix.


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