Neutron scattering and scaling behavior in URu2Zn20 and YbFe2Zn20

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.82.184407· OSTI ID:1001283

Wang, C. H. ^[1]; Christianson, Andrew D ^[2]; Lawrence, J. M. ^[1]; Bauer, E. D. ^[3]; Goremychkin, E. A. ^[4]; Kolesnikov, A. I. ^[4]; Trouw, F. ^[3]; Ronning, F. ^[3]; Thompson, J. D. ^[3]; Lumsden, Mark D ^[2]; Ni, N. ^[5]; Mun, E. D. ^[5]; Jia, S. ^[5]; Canfield, P. C. ^[6]

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1. University of California, Irvine
2. ORNL
3. Los Alamos National Laboratory (LANL)
4. Argonne National Laboratory (ANL)
5. Ames Laboratory and Iowa State University
6. Ames Laboratory

The dynamic susceptibility {chi}*({Delta}E), measured by inelastic neutron-scattering measurements, shows a broad peak centered at E{sub max} = 15 meV for the cubic actinide compound URu{sub 2}Zn{sub 20} and 7 meV at zone center and at the (1/2, 1/2, 1/2) zone boundary for the rare-earth counterpart compound YbFe{sub 2}Zn{sub 20}. For URu{sub 2}Zn{sub 20}, the low-temperature susceptibility and magnetic specific-heat coefficient {gamma} = C{sub mag}/T take the values {chi} = 0.011 emu/mole and {gamma} = 190 mJ/mole K{sup 2} at T = 2 K. These values are roughly three times smaller, and E{sub max} is three times larger, than recently reported for the related compound UCo{sub 2}Zn{sub 20}, so that {chi} and {gamma} scale inversely with the characteristic energy for spin fluctuations, T{sub sf} = E{sub max}/k{sub B}. While {chi}(T), C{sub mag}(T), and E{sub max} of the 4f compound YbFe{sub 2}Zn{sub 20} are very well described by the Kondo impurity model, we show that the model works poorly for URu{sub 2}Zn{sub 20} and UCo{sub 2}Zn{sub 20}, suggesting that the scaling behavior of the actinide compounds arises from spin fluctuations of itinerant 5f electrons.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Flux Isotope Reactor
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1001283
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 18 Vol. 82; ISSN 1098-0121; ISSN 1550-235X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACTINIDE COMPOUNDS
ELECTRONS
FLUCTUATIONS
NEUTRONS
SCATTERING
SPECIFIC HEAT
SPIN