Diffusion in Intermetallic Compounds Studied Using Nuclear Quadrupole Relaxation

Abstract:

The jump frequency of Cd tracer atoms was measured as a function of temperature in seven rare-earth tri-indide intermetallic compounds having the L12, or Cu3Au, structure. The frequency, proportional to the diffusivity, was detected by relaxation of nuclear quadrupole interaction at Cd nuclei caused by reorientation of the electric field gradient in each diffusive jump. Measurements were made using perturbed angular correlation of gamma rays, sensitive to jump frequencies in the range 1-1000 MHz. Results are as follows. (1) Jump frequencies measured in LaIn3 and CeIn3 were observed to be 10-100 times greater at the more In-rich boundary composition than the less In-rich boundary composition, even though the phases appear as line compounds in phase diagrams. (2) Arrhenius plots of the jump frequency were fitted to activation enthalpies that increase from 0.535 to 1.80 eV across the series of phases LaIn3, CeIn3, PrIn3, and NdIn3.

• Periodical: Defect and Diffusion Forum (Volumes 237-240)
• Pages: 195-200
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.237-240.195
• Online since: April 2005
• Authors: Gary Scott Collins, A. Favrot, L. Kang, D. Solodovnikov, Matthew O. Zacate
• Keywords: Diffusion, Indides, Line Compounds, Nuclear Quadrupole Interaction, Nuclear Relaxation, Perturbed Angular Correlation (PAC), Rare Earth Compounds

References

[1] Matthew O. Zacate, Aurélie Favrot and Gary S. Collins: Phys. Rev. Lett. Vol. 92 (2004), p.225901, and erratum.

[2] Jean Philibert: Atom movements: diffusion and mass transport in solids (Les Éditions de Physique, Les Ulis, France 1991).

[3] A. Baudry and P. Boyer: Hyperfine Interactions Vol. 35 (1987), p.803.

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[5] T.B. Massalski, editor: Binary Alloy Phase Diagrams (ASM International, Materials Park, OH, 1990, 2 nd edition).

[6] Matthew O. Zacate and Gary S. Collins: Physical Review B Vol. 69 (2004), p.174202.

[7] Matthew O. Zacate and Gary S. Collins: Physical Review B Vol. 70 (2004), p.24202.

[8] Matthew O. Zacate and Gary S. Collins: this conference. 4. 75 4. 70 4. 65 4. 60 4. 55 0. 0 0. 5 1. 0 1. 5 2. 0 La Ce Pr Nd Gd Er A B (Y) Q (eV) Lattice parameter (Å) Fig. 4. Jump frequency activation enthalpy as a function of lattice parameter for In3R phases (R= La, Ce, Pr, Nd, Gd, Y and Er ). Note the reversed lattice parameter scale. For La and Ce, filled and open symbols correspond to the more In-rich (A) and the less In-rich (B) phase boundary compositions.

DOI: 10.1021/acs.inorgchem.7b02319.s001