On the question of stability and disorder in icosahedral aluminum – transition metal alloys

1989 ◽  
Vol 67 (5) ◽  
pp. 463-467 ◽  
Author(s):  
D. W. Lawther ◽  
R. A. Dunlap ◽  
V. Srinivas
Keyword(s):  
Thermal Analysis ◽  
Transition Metal ◽  
Phase Formation ◽  
Strong Interaction ◽  
Metal Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Metal Alloys ◽  
Melt Spun

Through an X-ray diffraction and thermal analysis investigation of melt spun Al – transition metal (Al–TM) alloys, we report the formation of a highly stable and well-ordered pure icosahedral (i) phase in Al80TMl20−xTM2x(TM1 = V, Cr; TM2 = Fe, Co). The superior i-phase formation over that in the binary Al–TM alloys is interpreted in terms of the distribution of TM sites known to exist in this phase. A comparison of the i-phase formation ranges indicates the presence of two distinct classes of TM sites and a strong interaction between adjacent TM sites.

Amorphization of rapidly quenched quasicrystalline Al-transition metal alloys by the addition of Si

1986 ◽  
Vol 1 (3) ◽  
pp. 415-419 ◽  
Author(s):  
R.A. Dunlap ◽  
K. Dini
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Metal Alloys ◽  
Icosahedral Symmetry ◽  
Quench Rate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Metal Alloys ◽  
Rapidly Solidified ◽  
Thermal Stability Of

The structure and thermal stability of rapidly solidified Al-Cr-Si, Al-Mn-Si, Al-Fe-Si, Al-Co-Si, and Al-Ni-Si alloys have been investigated using x-ray diffraction and thermal analysis measurements. Each series of alloys shows a region of stoichiometry that yields icosahedral symmetry and a region that yields an amorphous phase. Thermal and structural properties of these alloys are reported as a function of stoichiometry and quench rate.

Formation, structure, and crystallization of metastable quasi-crystalline Al–transition metal alloys prepared by rapid solidification

1985 ◽  
Vol 63 (10) ◽  
pp. 1267-1269 ◽  
Author(s):  
R. A. Dunlap ◽  
K. Dini
Keyword(s):  
Thermal Analysis ◽  
Transition Metal ◽  
Crystallite Size ◽  
Crystal Structures ◽  
Rapid Solidification ◽  
Rapid Quenching ◽  
Metal Alloys ◽  
X Ray ◽  
Transition Metal Alloys ◽  
Diffraction Peaks

Metastable Al86Cr14, Al86Mn14, and Al86Fe14 were prepared by rapid quenching from the melt at a rate of approximately 2 × 106 K/s. The X-ray measurements of all three alloys show similar non-Bravais structures. Broadened diffraction peaks for the Al–Fe alloy suggest a crystallite size of about 60 Å. Thermal-analysis measurements show that all of the alloys transform into conventional crystal structures at approximately 670. The crystalline phases for the three alloys are Al11Cr2 + Al, Al6Mn + Al, and Al6Fe + Al. At approximately 800 K, Al–Fe undergoes the further transition Al6Fe → Al3Fe + Al.

Soft X-Ray Absorption and Electronic Structure of Al-Based 3d-Transition Metal Alloys

1979 ◽  
Vol 46 (2) ◽  
pp. 599-607 ◽  
Author(s):  
Takaaki Hanyu ◽  
Shigeo Yamaguchi ◽  
Hideaki Koike ◽  
Shigeru Sato
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Metal Alloys ◽  
X Ray ◽  
Transition Metal Alloys ◽  
X Ray Absorption

scholarly journals Magneto-x-ray effects in transition-metal alloys

1997 ◽  
Vol 55 (19) ◽  
pp. 12826-12828 ◽  
Author(s):  
H. J. Gotsis ◽  
P. Strange
Keyword(s):  
Transition Metal ◽  
Metal Alloys ◽  
X Ray ◽  
Transition Metal Alloys ◽  
Ray Effects

scholarly journals The Effect of Calcination Temperature on the Structure and Performance of Nanocrystalline Mayenite Powders

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3476 ◽  
Author(s):  
Katarzyna Berent ◽  
Sebastian Komarek ◽  
Radosław Lach ◽  
Waldemar Pyda
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Calcination Temperature ◽  
Phase Formation ◽  
Crystalline Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Appreciable Increase ◽  
And Performance

The effect of calcination temperature on the structural properties and phase formation of synthesized CaO-Al2O3 nanopowder was investigated and discussed. The calcination products were identified by differential thermal analysis (DTA) and the crystalline phase formation was analyzed by X-ray diffraction (XRD). The obtained results showed that the crystallization started at 460 °C. Finally, the microstructures of the nanoparticles were observed by scanning (SEM) and transmission electron (TEM) microscopes. The investigation showed that an increase in the calcination temperature led to the appreciable increase in the crystallite size and the crystallinity of the final product. The obtained data confirmed that the prepared materials were mayenite with different surface area in the range of 71.18 m2/g to 10.34 m2/g after annealing in the temperature range of 470 °C to 960 °C.

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