The giant magnetostriction observed in rare-earth transition-metal compounds such as Terfenol-D (Tb0.3Dy0.7Fe2) is commonly associated with the huge anisotropy of the 4f electron cloud. We report here the experimental observation of this phenomenon at the atomic scale, in amorphous matter. By using extended x-ray absorption fine structure spectroscopy in a differential mode, the bond strains resulting from the coupling between the anisotropic shape of the Tb 4f charge density and the environment crystalline electric field are measured. In a-TbFe2 we measure Fe-Fe and Fe-Tb bond contractions equal to 6(1)x 10−4 Å and of 9(2) x 10−4 Å, respectively. These are the smallest atomic displacements ever detected in amorphous matter.
4f charge-density deformation and magnetostrictive bond strain observed in amorphous TbFe2 by x-ray absorption spectroscopy / S.PASCARELLI; M.P.RUFFONI; A.TRAPANANTI; O.MATHON; C. DETLEFS; M.PASQUALE; MAGNI A; C.P.SASSO; F.CELEGATO; E.OLIVETTI; Y.JOLY; AND D.GIVORD. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 81(2010), pp. 020406-1-020406-4.
Titolo: | 4f charge-density deformation and magnetostrictive bond strain observed in amorphous TbFe2 by x-ray absorption spectroscopy |
Autori: | |
Data di pubblicazione: | 2010 |
Rivista: | |
Citazione: | 4f charge-density deformation and magnetostrictive bond strain observed in amorphous TbFe2 by x-ray absorption spectroscopy / S.PASCARELLI; M.P.RUFFONI; A.TRAPANANTI; O.MATHON; C. DETLEFS; M.PASQUALE; MAGNI A; C.P.SASSO; F.CELEGATO; E.OLIVETTI; Y.JOLY; AND D.GIVORD. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 81(2010), pp. 020406-1-020406-4. |
Abstract: | The giant magnetostriction observed in rare-earth transition-metal compounds such as Terfenol-D (Tb0.3Dy0.7Fe2) is commonly associated with the huge anisotropy of the 4f electron cloud. We report here the experimental observation of this phenomenon at the atomic scale, in amorphous matter. By using extended x-ray absorption fine structure spectroscopy in a differential mode, the bond strains resulting from the coupling between the anisotropic shape of the Tb 4f charge density and the environment crystalline electric field are measured. In a-TbFe2 we measure Fe-Fe and Fe-Tb bond contractions equal to 6(1)x 10−4 Å and of 9(2) x 10−4 Å, respectively. These are the smallest atomic displacements ever detected in amorphous matter. |
Handle: | http://hdl.handle.net/11696/33537 |
Appare nelle tipologie: | 1.1 Articolo in rivista |