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Influence of Composition on the Structure and Properties of Fe-Pd-P and Ni-Pd-P Amorphous Alloys

Citation

Maitrepierre, Philippe Louis (1969) Influence of Composition on the Structure and Properties of Fe-Pd-P and Ni-Pd-P Amorphous Alloys. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/8VCG-6E08. https://resolver.caltech.edu/CaltechTHESIS:02192014-085423804

Abstract

Ternary alloys of nickel-palladium-phosphorus and iron-palladium-phosphorus containing 20 atomic % phosphorus were rapidly quenched from the liquid state. The structure of the quenched alloys was investigated by X-ray diffraction. Broad maxima in the diffraction patterns, indicative of a glass-like structure, were obtained for 13 to 73 atomic % nickel and 13 to 44 atomic % iron, with palladium adding up to 80%.

Radial distribution functions were computed from the diffraction data and yielded average interatomic distances and coordination numbers. The structure of the amorphous alloys could be explained in terms of structural units analogous to those existing in the crystalline Pd3P, Ni3P and Fe3P phases, with iron or nickel substituting for palladium. A linear relationship between interatomic distances and composition, similar to Vegard's law, was shown for these metallic glasses.

Electrical resistivity measurements showed that the quenched alloys were metallic. Measurements were performed from liquid helium temperatures (4.2°K) up to the vicinity of the melting points (900°K-1000°K). The temperature coefficient in the glassy state was very low, of the order of 10-4/°K. A resistivity minimum was found at low temperature, varying between 9°K and 14°K for Nix-Pd80-x -P20 and between 17°K and 96°K for Fex-Pd80-x -P20, indicating the presence of a Kondo effect. Resistivity measurements, with a constant heating rate of about 1.5°C/min,showed progressive crystallization above approximately 600°K.

The magnetic moments of the amorphous Fe-Pd-P alloys were measured as a function of magnetic field and temperature. True ferromagnetism was found for the alloys Fe32-Pd48-P20 and Fe44-Pd36-P20 with Curie points at 165° K and 380° K respectively. Extrapolated values of the saturation magnetic moments to 0° K were 1.70 µB and 2.10 µB respectively. The amorphous alloy Fe23-Pd57-P20 was assumed to be superparamagnetic. The experimental data indicate that phosphorus contributes to the decrease of moments by electron transfer, whereas palladium atoms probably have a small magnetic moment. A preliminary investigation of the Ni-Pd-P amorphous alloys showed that these alloys are weakly paramagnetic.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Materials Science) ; amorphous metallic alloys
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Materials Science
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Duwez, Pol E.
Thesis Committee:
  • Unknown, Unknown
Defense Date:17 March 1969
Funders:
Funding AgencyGrant Number
Atomic Energy CommissionUNSPECIFIED
Record Number:CaltechTHESIS:02192014-085423804
Persistent URL:https://resolver.caltech.edu/CaltechTHESIS:02192014-085423804
DOI:10.7907/8VCG-6E08
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:8084
Collection:CaltechTHESIS
Deposited By: Benjamin Perez
Deposited On:19 Feb 2014 17:27
Last Modified:03 May 2024 20:33

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