Portal de Periódicos da CAPES

57Fe mössbauer spectroscopy of U6Fe

1987; Elsevier BV; Volume: 127; Linguagem: Inglês

10.1016/0022-5088(87)90417-6

1878-2728

G. Lemon, P. Boolchand, Mark J. Stevens, M. Marcuso, L. E. DeLong, J.G. Huber,

High-pressure geophysics and materials

Samples of U6Fe were prepared by arc melting uranium and enriched 57Fe. The samples display superconducting transitions which are sensitive to longterm exposure to air. Room temperature spectra of U6Fe typically display a majority site A (quadrupole splitting Δ = 0.749(3)mm s−1, isomer shift δ = − 0.482(6)mm s−1 relative to copper and a minority site B (Δ = 0.55(3) mm s−1, δ = −0.12(3)mms−1 with the site intensity ratio IBIA typically 0.05 to 0.10. The IBIA intensity ratio increases upon air exposure of the samples. We have studied Mössbauer spectra as a function of temperature Tin the range 15K⩽ T ⩽ 310K, paying particular attention to the T variation of the isomer shift and recoil-free fraction of the majority site A. The results indicate a softening of lattice vibrations of U6Fe at T ≲ 170 K.