Naslov
Effects of magnetic ordering on dynamical conductivity : Optical investigations of EuFe2As2 single crystals

Autori
Wu, D. ; Barišić, Neven ; Drichko, N. ; Kaiser, S. ; Faridian, A. ; Dressel, M. ; Jiang, S. ; Ren, Z. ; Li, L.J. ; Cao, G.H. ; Xu, Z.A. ; Jeevan, H.S. ; Gegenwart, P.

Izvornik
Physical Review B - Condensed Matter and Materials Physics (1098-0121) 79 (2009); 155103-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
EuFe2As2; optical conductivity

Sažetak
The magnetic, transport, and optical properties of EuFe2As2 single crystals have been investigated parallel and perpendicular to the ab plane. The anisotropy rho(c)/rho(ab)approximate to 8 depends only slightly on temperature. In both orientations, the spin-density-wave transition at T-SDW=189 K shows up as a considerable increase in the dc resistivity. Susceptibility measurements evidence the magnetic order of the Eu2+ moments at T-N=19 K with little influence on the electronic transport taking place in the FeAs layers. Polarization-dependent infrared spectroscopy reveals strongly anisotropic optical properties and yields a carrier density of only 4.2x10(21) cm(-3) and a bandmass of m(b)=2m(0). A sizeable Drude contribution is present at all temperatures and narrows upon cooling. Below T-SDW, the spin- density-wave gap develops in the in-plane optical conductivity ; no appreciable change is detected for the perpendicular polarization. Modifications in the phonon features are associated with changes in the electronic properties at T-SDW. The extended Drude analysis yields a linear behavior of the frequency-dependent scattering rate below T-SDW, indicating an interaction between the charge carriers and spin fluctuations in the spin- density-wave state

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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