Estudo de ordenamento multipolar eletrico de holmio por difração de raios-X

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

Multipolar ordering in metallic holmium 4f shell was extensively studied for the first time, by resonant and non resonant X-ray scattering at the helical antiferromagnetic and conical ferromagnetic phases. The strong spin-orbit coupling drives the multipolar order as it was experimentally confirmed through the temperature dependence of the ordering wave-vector t . The quadrupolar nature of the 2 t and 4 t satellite peaks, measured in the non-resonant regime, were in good agreement with calculations of the form factor Q- dependence. Non magnetic satellite peaks observed at t in the ferromagnetic phase correspond to the conical ordering of the 4f quadrupoles strongly coupled to the magnetic ordering. Positive and negative interference effects at 2 t measured with resonant X-ray scattering at Ho L3 edge correspond to the addition or subtraction of the magnetic and quadrupolar resonant enhancements at the s-p polarization channel and at the quadrupolar transition 2p ® 4f. An apparent "phase inversion" observed for the 2 t and 4 t satellite peaks was interpreted using the anisotropic tensor susceptibility (ATS) theory applied to incommensurate systems. The construction and commissioning of the XRD2 beamline at the Brazilian Synchrotron Light Laboratory (LNLS) dedicated to the study of charge, orbital and magnetic structures was also an important part of this work

ASSUNTO(S)

ressonancia - difração sincrotron metais de terras raras raios x - difração

ACESSO AO ARTIGO

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