Electronic properties of *-oriented thin films

Foerster, Michael; Jourdan, Martin; Zakharov, A.; Herbort, Christian; Adrian, H.

doi:10.1016/j.jmmm.2006.10.064

Cited by 4 publications

(2 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First experiments on thin films of UNi 2 Al 3 have revealed similar Drude behavior in the GHz range,[40] but more detailed investigations on this compound are necessary before final conclusions can be drawn.An aspect of particular interest here is the anisotropy of the microwave conductivity: a modification of the present spectrometer allows for the study of anisotropic materials if they are available as thin films with the anisotropy in the plane [41]. Such studies of anisotropic optical properties are under way for UNi 2 Al 3 ,[42] and they could also be performed on a * -oriented thin films of UPd 2 Al 3 [43]. Additional studies of the microwave conductivity on other heavy-fermion materials, in particular based on Ce or Yb instead of U, would be desired to demonstrate whether the extremely low relaxation is generic for heavy-fermion compounds.…”

mentioning

confidence: 99%

Microwave conductivity of heavy fermions in UPd2Al3

2010

View full text Add to dashboard Cite

Abstract. Heavy-fermion compounds are characterized by electronic correlation effects at low energies which can directly be accessed with optical spectroscopy. Here we present detailed measurements of the frequency-and temperature-dependent conductivity of the heavy-fermion compound UPd2Al3 using broadband microwave spectroscopy in the frequency range 45 MHz to 40 GHz at temperatures down to 1.7 K.We observe the full Drude response with a relaxation time up to 50 ps, proving that the mass enhancement of the heavy charge carriers goes hand in hand with an enhancement of the relaxation time. We show that the relaxation rate as a function of temperature scales with the dc resistivity. We do not find any signs of a frequency-dependent relaxation rate within the addressed frequency range. PACS

show abstract

mentioning

confidence: 99%

Microwave conductivity of heavy fermions in UPd2Al3

2010

View full text Add to dashboard Cite

show abstract

“…1,23 Both of them have a hexagonal crystal structure, and an anisotropy in the transport properties along the a-and c-axes. 24,25 UPd 2 Al 3 has a commensurable antiferromagnetic phase below 14.5 K with a magnetic moment of 0.85µ B . 26 For UNi 2 Al 3 the phase transition to the antiferromagnetically ordered state takes place at T N = 4.6 K. Here the order is incommensurable with a magnetic moment of 0.24µ B .…”

Section: Introductionmentioning

confidence: 99%

Terahertz conductivity of the heavy-fermion compound UNi2Al3

Ostertag,

Scheffler,

Dressel

et al. 2011

Preprint

View full text Add to dashboard Cite

We have studied the optical properties of the heavy-fermion compound UNi2Al3 at frequencies between 100 GHz and 1 THz (3 cm −1 and 35 cm −1 ), temperatures between 2 K and 300 K, and magnetic fields up to 7 T. From the measured transmission and phaseshift of radiation passing through a thin film of UNi2Al3, we have directly determined the frequency dependence of the real and imaginary parts of the optical conductivity (or permittivity, respectively). At low temperatures the anisotropy of the optical conductivity along the a-and c-axes is about 1.5. The frequency dependence of the real part of the optical conductivity shows a maximum at low temperatures, around 3 cm −1 for the a-axis and around 4.5 cm −1 for the c-axis. This feature is visible already at 30 K, much higher than the Néel temperature of 4.6 K, and it does not depend on external magnetic fields as high as 7 T. We conclude that this feature is independent of the antiferromagnetic order for UNi2Al3, and this might also be the case for UPd2Al3 and UPt3, where a similar maximum in the optical conductivity was observed previously [M. Dressel et al., Phys. Rev. Lett. 88, 186404 (2002)].

show abstract