AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

APFIM Studies of Nanocrystallizations of Amorphous Alloys

1995 ◽  
Vol 400 ◽  
Author(s):  
K. Hono ◽  
Y. Zhang ◽  
A. Inoue ◽  
T. Sakurai
Keyword(s):  
Amorphous Alloys ◽  
Amorphous Matrix ◽  
Primary Crystallization ◽  
Atom Probe ◽  
Nucleation And Growth ◽  
Cu Alloy ◽  
Nucleation Sites ◽  
Medium Range ◽  
Crystallization Reaction ◽  
Primary Crystals

AbstractThis paper reports recent atom probe analysis results of Fe-Zr-B(-Cu) and Al-Ni-Ce(-Cu) amorphous alloys, in which nanocrystalline microstructures develop by primary crystallization. In these alloy systems, enrichment of slow diffusing solute was found at the interfaces between primary crystals and amorphous matrix during the nucleation and growth stage. In the case of ternary Fe-Zr-B, no evidence for compositional heterogeneities were found prior to the onset of crystallization reaction. On the other hand, clustering of Cu atoms was observed in quaternary Fe-Zr-B-Cu alloy prior to the crystallization reaction. In the ternary Fe-Zr-B alloy, nucleation sites seem to be provided by the quenched-in nuclei which were observed as medium range ordered (MRO) domains by HREM. In the as-quenched Al-Ni-Ce(-Cu) alloy, compositional fluctuations were present from the as-quenched state. These observations suggest that nuclei for primary crystallization are provided in various forms such as MRO domains, solute clusters and compositional heterogeneities.

Physical Properties of Partially Crystallized Fe80B20 Amorphous Alloys

1995 ◽  
Vol 400 ◽  
Author(s):  
D. Fiorani ◽  
F. Malizia ◽  
F. Ronconi ◽  
M. Vittori Antisari
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Growth Process ◽  
Magnetic Hyperfine Field ◽  
Nucleation And Growth ◽  
Hyperfine Fields ◽  
Low Field ◽  
Transmission Electron ◽  
Mössbauer Spectrometer ◽  
Radial Structure

AbstractThe magnetic properties and hyperfine fields were investigated at low temperatures on amorphous Fe80B20 ribbons crystallized at the end of the nucleation-and-growth process without involving coarsening process. The results obtained by SQUID magnetometer and Mössbauer spectrometer show that saturation magnetization and mean magnetic hyperfine field values are greater than those in both the parent amorphous phase and in the fully crystallized structure where coarsening and grain growth processes are involved. Below 200 K irreversibility is observed in low field magnetization measurements. Transmission electron microscopy measurements reveal that spherulites of Fe3B include a radial structure made of small bcc-Fe acicular crystals about 200 nm long and 10 nm wide. In our opinion, magnetic properties and hyperfine fields are ruled by both high magnetic anisotropy of small monodomain acicular bcc-Fe crystallites and the structure of Fe atoms located at their surfaces.

Electrical and magnetic properties in Co-P amorphous alloys

1986 ◽  
Vol 60 (2-3) ◽  
pp. 195-198 ◽  
Author(s):  
J.M. Riveiro ◽  
M.C. Sánchez-Trujillo ◽  
G. Rivero
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Electrical And Magnetic Properties

Thermal, Electrical, and Magnetic Properties of the Amorphous Alloys RExSi1–x (RE = Gd or Tb;x = 0.87, 0.59, 0.18)

1986 ◽  
Vol 98 (2) ◽  
pp. 551-566 ◽  
Author(s):  
P. Simonnin ◽  
R. Tourbot ◽  
B. Boucher ◽  
M. Perrin ◽  
J. Vanhaute
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Electrical And Magnetic Properties

Characterization of Superconducting BSCCO/CaSiO3 and BSCCO/CaZrO3 Ag PIT Wires

2014 ◽  
Vol 975 ◽  
pp. 106-110
Author(s):  
Natacha Andréia Nogueira ◽  
Anne Hitome Yonamine ◽  
Dayse Iara dos Santos ◽  
Jung Ho Kim ◽  
Shi Xue Dou
Keyword(s):  
Magnetic Properties ◽  
Partial Melting ◽  
Critical Current ◽  
Calcium Silicate ◽  
Calcium Zirconate ◽  
Melting Method ◽  
Electrical And Magnetic Properties ◽  
Current Densities ◽  
Powder In Tube

The addition of two compounds, calcium silicate and calcium zirconate was tested, in the preparation of Bi: 2212 silver sheathed wires by powder-in-tube method, which were successfully tested previously in processing chips. The wires were treated in an atmosphere of O2/Ar using partial melting method. The characterizations were structural and on their electrical and magnetic properties. As the results, transition temperatures were higher than the expected for this stage, ranged from 105K (BSCCO880) to 116K (+Si883). The critical current densities encountered in transport and magnetization measurements were improved in comparison with the wires without addition.

Effect of Annealing on the Curie Temperature in the Bulk Amorphous Alloys

2017 ◽  
Vol 68 (8) ◽  
pp. 1903-1907 ◽  
Author(s):  
Bartlomiej Jez
Keyword(s):  
Curie Temperature ◽  
Amorphous Alloys ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Annealing Process ◽  
Amorphous Phases ◽  
Bulk Amorphous Alloys ◽  
Partial Crystallization ◽  
Curie Temperatures ◽  
Thermal Interference

The paper presents results of research for volumetric amorphous alloys Fe61+xCo10-XY8W1B20 where x = 0,12 in the shape of plater of 10mm x 5mm x 0.5mm diameter. Amorphous Samales were annealed at 953K for 10 minutes what caused their partial crystallization. As a result of the thermal interference in the volume of alloys, three different crystalline phases were formed aFe, Fe5Y and Fe3B. For samples after solidification and after thermal treatment thermomagnetic studiem were conducted. For amorphous alloys, only one ferro-paramagnetic transition was visible, and for the alloys after the isothermal annealing process there were two inflections on the curve .m0Ms (T) corresponding to the two Curie temperatures. These intersections came from two amorphous phases. As a result of the research, it was found that these alloys crystallized in the primal crystalization. Crystallization was the reason for the increase of the first Curie temperature of the amorphous matrix while retaining its decrease with cobalt additive. The value of the second Curie temperature in the alloys after heating was found to depend mainly on the size of the crystallization products and in particular on the Fe5Y crystallite size.

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