Search for instability-induced amorphization in deuterated ErFe[sub 2]

Journal Article · Sun Aug 01 04:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.3689· OSTI ID:6354440

Krill, III, C E; Li, J ^[1]; Yelon, W B ^[2]; Johnson, W L ^[1]

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1. W. M. Keck Laboratory of Engineering Materials 138-78, California Institute of Technology, Pasadena, California 91125 (United States)
2. University of Missouri Research Reactor and Department of Physics, University of Missouri-Columbia, Columbia, Missouri 65211 (United States)

Experimental evidence--in the form of a specific-heat anomaly--for instability-induced amorphization of ErFe[sub 2] by hydrogenation was recently reported by Fecht, Fu, and Johnson [Phys. Rev. Lett. 64, 1753 (1990)]. We have attempted to study this anomaly by [ital in] [ital situ] elastic neutron diffraction and differential-scanning-calorimetry (DSC) measurements of deuterated ErFe[sub 2] below and above the reversible, endothermic, [lambda]-shaped enthalpy signal that they found at [similar to]200 [degree]C. Our combined diffraction and DSC results reveal that the amorphization transition is irreversible, strongly exothermic and occurs only at a significantly higher temperature than that of the specific-heat anomaly. Rather than resulting from an underlying instability of the crystalline phase, amorphization occurs as a by-product of short-range clustering of the Er and Fe atoms, which is driven by the creation of energetically more favorable sites for the deuterium atoms.

• DOE Contract Number: FG05-89ER75511; FG03-86ER45242
• OSTI ID: 6354440
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:6; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
AMORPHOUS STATE
ATOMIC CLUSTERS
CALORIMETRY
CHEMICAL REACTIONS
COHERENT SCATTERING
DEUTERATION
DIFFRACTION
ERBIUM COMPOUNDS
INSTABILITY
IRON COMPOUNDS
NEUTRON DIFFRACTION
RARE EARTH COMPOUNDS
SCATTERING
TRANSITION ELEMENT COMPOUNDS