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Register a new userThickness dependence of the ground-state properties in thin films of the heavy-fermion compound CeCu_6
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Added by
G. J. C. van Baarle
Publication date
2001
fields
Physics
and research's language is
English
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High-quality thin polycrystalline films of the heavy-fermion compound CeCu_6 were prepared by sputter deposition. The thicker of these films (with thickness up to around 200 nm) reproduce the properties of the bulk compound CeCu_6. As the thickness of the films is decreased, our measurements display strong deviations from the bulk properties, namely, a suppression of the heavy-fermion state. We show that possible `external effects, like disorder, oxidation and morphology can be excluded and that this size effect is therefore an intrinsic property of CeCu_6. In addition, we investigate possible scenarios explaining the size effect, and find that the proximity of CeCu_6 to a quantum phase transition can account for this striking result.
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We report results from neutron scattering experiments on single crystals of YbBiPt that demonstrate antiferromagnetic order characterized by a propagation vector, $tau_{rm{AFM}}$ = ($frac{1}{2} frac{1}{2} frac{1}{2}$), and ordered moments that align along the [1 1 1] direction of the cubic unit cell. We describe the scattering in terms of a two-Gaussian peak fit, which consists of a narrower component that appears below $T_{rm{N}}~approx 0.4$ K and corresponds to a magnetic correlation length of $xi_{rm{n}} approx$ 80 $rm{AA}$, and a broad component that persists up to $T^*approx$ 0.7 K and corresponds to antiferromagnetic correlations extending over $xi_{rm{b}} approx$ 20 $rm{AA}$. Our results illustrate the fragile magnetic order present in YbBiPt and provide a path forward for microscopic investigations of the ground states and fluctuations associated with the purported quantum critical point in this heavy-fermion compound.
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