scholarly journals Atomic Distribution in Catalytic Amorphous Metals

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Sanghita Mridha ◽  
David L. Jaeger ◽  
Harpreet Singh Arora ◽  
Rajarshi Banerjee ◽  
Sundeep Mukherjee
Keyword(s):  
Phase Separation ◽  
Metallic Glass ◽  
Amorphous Alloys ◽  
Three Dimensional ◽  
Atom Probe ◽  
Glassy Alloys ◽  
Atomic Distribution ◽  
Liquid Behavior ◽  
Catalytically Active ◽  
Constituent Elements

The atomic distribution in catalytically active metallic glass alloys, Pd43Cu27Ni10P20and Pt57.5Cu14.7Ni5.3P22.5, was investigated using three-dimensional atom probe microscopy. Atom probe analysis showed uniform distribution of constituent elements for both the starting amorphous alloys, with no phase separation. Both the crystallized alloys showed eutectic microstructure with a very sharp interface (~0.5 nm as determined from atom probe). The atomic distribution in the devitrified state is explained based on the “fragile liquid” behavior for these noble-metal glassy alloys.

Ordering and phase separation in Ni–Cr–Al: Monte Carlo simulations vs three-dimensional atom probe

1999 ◽  
Vol 47 (6) ◽  
pp. 1889-1899 ◽  
Author(s):  
C. Pareige ◽  
F. Soisson ◽  
G. Martin ◽  
D. Blavette
Keyword(s):  
Monte Carlo ◽  
Phase Separation ◽  
Monte Carlo Simulations ◽  
Three Dimensional ◽  
Atom Probe

Effect of Cu On Microstructural Evolution of Nanocrystalline Soft and Hard Magnetic Materials

1999 ◽  
Vol 577 ◽  
Author(s):  
K. Hono ◽  
D. H. Ping ◽  
S. Hirosawa
Keyword(s):  
Amorphous Alloys ◽  
Three Dimensional ◽  
Atom Probe ◽  
Hard Magnetic Materials ◽  
Atom Clusters ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Final Microstructure ◽  
Crystallization Reaction ◽  
Primary Crystals

ABSTRACTThe nanocrystallization processes in Fe-Si-B-Nb-Cu and Fe-Nd-B(-Cu-Nb) amorphous alloys have been studied by transmission electron microscopy (TEM) and a three dimensional atom probe (3DAP). Cu additions are effective in refining the nanocrystalline microstructures of both alloys, because Cu atom clusters formed prior to the crystallization reaction serve as heterogeneous nucleation sites for the primary crystals. However, the clustering behaviors of Cu atoms in these two alloy systems are different, i.e., Cu completely dissolves in the Nd2Fe1 4B phase in the final microstructure of the Nd4.5Fe75.8B18.5Cu0.2Nb1 alloy, whereas CL' clusters grow to fcc-Cu particles in the Fe73.5Si13.5B9Nb3Cu1 alloy. The nanocrystallization processes in these two alloys clarified by the 3DAP results are compared.

Early stages of phase separation using three-dimensional atom probe and atomistic modelling

2007 ◽  
Vol 39 (2-3) ◽  
pp. 178-183 ◽  
Author(s):  
Mattias Slabanja ◽  
Johan Angenete ◽  
Krystyna Stiller ◽  
Karin M. Carling ◽  
Göran Wahnström ◽  
...  
Keyword(s):  
Phase Separation ◽  
Three Dimensional ◽  
Atom Probe ◽  
Early Stages ◽  
Atomistic Modelling

The β'-α' Interaction: a Study of early Stages of Phase Separation in a Fe-20%Cr-6%Al-0.5%Ti Alloy

2011 ◽  
Vol 172-174 ◽  
pp. 315-320
Author(s):  
Carlos Capdevila ◽  
Michael K. Miller ◽  
K.F. Russell ◽  
J. Chao ◽  
F.A. López
Keyword(s):  
Phase Separation ◽  
Atom Probe Tomography ◽  
Temporal Evolution ◽  
Theoretical Calculations ◽  
Three Dimensional ◽  
Atom Probe ◽  
Early Stages ◽  
Β Phase ◽  
Α Phase ◽  
Power Measurements

The temporal evolution of the microstructure resulting from phase separation into Fe-rich (α), Cr-rich (α¢), and Fe(Ti,Al) (β¢) phases of a Fe-20Cr-6Al-0.5Ti alloy has been analyzed by thermoelectric power measurements (TEP). The early stages of decomposition and the evolution of the three-dimensional microstructure have been analyzed by atom probe tomography (APT). The roles of Cr, Al, and Ti during the decomposition process have been investigated in terms of solute partitioning between the phases. Analysis of proximity histograms revealed that significant Al and Ti partitioning occurs, which is consistent with theoretical calculations. The results indicate that as the α-α¢ phase separation proceeds, Al and Ti are rejected into the α phase, which causes the β¢ phase to nucleate on the surface of the α¢ phase.

Structural Stability and Elasticity in Zr-Based Bulk Metallic Glasses

2007 ◽  
Vol 561-565 ◽  
pp. 1391-1395 ◽  
Author(s):  
Shuo Zhang ◽  
T. Ichitsubo ◽  
Yokoyama Yoshihiko ◽  
K. Miyagi ◽  
Eiichiro Matsubara
Keyword(s):  
Thermal Stability ◽  
Metallic Glass ◽  
Bulk Modulus ◽  
Bulk Metallic Glass ◽  
Structural Stability ◽  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Coordination Numbers ◽  
Constituent Elements ◽  
Thermal Stability Of

The structure, thermal stability and elasticity of Zr50Cu40Al10 bulk metallic glass (BMG) have been investigated with reference to Zr70Cu30 and Zr70Cu20Al10 amorphous alloys. The thermal stability of Zr50Cu40Al10 is significantly enhanced in comparison compared with those of the others. The large total coordination numbers more than 11 around all constituent elements are observed in Zr50Cu40Al10. A change of the bulk modulus in the crystallization is extremely small in Zr50Cu40Al10. The present experimental results indicate that atoms in the Zr50Cu40Al10 glass are closely packed and its microstructure is fairly uniform. This results in the much higher thermal stability of Zr50Cu40Al10.

Decomposition in Pd40Ni40P20 Bulk Metallic Glass

1998 ◽  
Vol 554 ◽  
Author(s):  
M. K. Miller ◽  
R. B. Schwarz ◽  
Yi He
Keyword(s):  
Phase Separation ◽  
Metallic Glass ◽  
Cast Alloy ◽  
Atom Probe ◽  
Probe Field ◽  
3 Dimensional ◽  
Short Range Ordering ◽  
Field Ion Microscope ◽  
Temperature Crystallization

AbstractAn atom probe field ion microscope and 3-dimensional atom probe characterization of the solute distribution in a bulk Pd40Ni40P20 metallic glass in the as-cast state and after annealing has been performed. Statistical analysis of the atom probe atom-by-atom data detected the presence of short range ordering in the as-cast alloy. Phase separation at the nanometer level is observed in glassy samples after annealing above the glass-transition temperature. Crystallization proceeds by phase separation into three distinct crystalline phases. Atom probe analysis of the alloy annealed for 1 h at 410°C revealed that the primary nickel phosphide phase contained significant levels of palladium, the palladium-rich Pd3P phosphide phase contained low levels of nickel and there was a small amount of a palladium-nickel solid solution.

Evolution of atomic distribution during devitrification of bulk metallic glass investigated by atom probe microscopy

2015 ◽  
Vol 158 ◽  
pp. 99-103 ◽  
Author(s):  
Sanghita Mridha ◽  
David L. Jaeger ◽  
Harpreet Singh Arora ◽  
Rajarshi Banerjee ◽  
Sundeep Mukherjee
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Atom Probe ◽  
Probe Microscopy ◽  
Atomic Distribution

A new method for mapping the three-dimensional atomic distribution within nanoparticles by atom probe tomography (APT)

2018 ◽  
Vol 190 ◽  
pp. 30-38 ◽  
Author(s):  
Se-Ho Kim ◽  
Phil Woong Kang ◽  
O Ok Park ◽  
Jae-Bok Seol ◽  
Jae-Pyoung Ahn ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Three Dimensional ◽  
Atom Probe ◽  
New Method ◽  
Atomic Distribution

Three-dimensional atom probe study of Fe–B-based nanocrystalline soft magnetic materials

2009 ◽  
Vol 57 (15) ◽  
pp. 4463-4472 ◽  
Author(s):  
Y.M. Chen ◽  
T. Ohkubo ◽  
M. Ohta ◽  
Y. Yoshizawa ◽  
K. Hono
Keyword(s):  
Magnetic Materials ◽  
Three Dimensional ◽  
Atom Probe ◽  
Soft Magnetic Materials ◽  
Soft Magnetic
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