Neutron scattering and scaling behavior in URu2Zn20 and YbFe2Zn20

TitleNeutron scattering and scaling behavior in URu2Zn20 and YbFe2Zn20
Publication TypeJournal Article
Year of Publication2010
AuthorsWang CH, Christianson AD, Lawrence JM, Bauer ED, Goremychkin EA, Kolesnikov AI, Trouw F, Ronning F, Thompson JD, Lumsden MD, Ni N, Mun ED, Jia S, Canfield PC, Qiu Y, Copley JRD
Journal TitlePhysical Review B
Volume82
Pages184407
Date Published11/05
ISBN Number1098-0121
Accession NumberISI:000283841000003
Keywordsco, excitations, fluctuations, INTERMETALLIC COMPOUND, IR, RH, upt3, URANIUM
Abstract

The dynamic susceptibility chi '' (Delta E), measured by inelastic neutron-scattering measurements, shows a broad peak centered at E-max=15 meV for the cubic actinide compound URu2Zn20 and 7 meV at zone center and at the (1/2, 1/2, 1/2) zone boundary for the rare-earth counterpart compound YbFe2Zn20. For URu2Zn20, the low-temperature susceptibility and magnetic specific-heat coefficient gamma = C-mag/T take the values chi = 0.011 emu/mole and gamma = 190 mJ/mole K-2 at T=2 K. These values are roughly three times smaller, and E-max is three times larger, than recently reported for the related compound UCo2Zn20, so that chi and gamma scale inversely with the characteristic energy for spin fluctuations, T-sf = E-max/k(B). While chi(T) , C-mag(T), and E-max of the 4f compound YbFe2Zn20 are very well described by the Kondo impurity model, we show that the model works poorly for URu2Zn20 and UCo2Zn20, suggesting that the scaling behavior of the actinide compounds arises from spin fluctuations of itinerant 5f electrons.

URL<Go to ISI>://000283841000003http://prb.aps.org/pdf/PRB/v82/i18/e184407
DOI10.1103/Physrevb.82.184407
Alternate JournalPhys Rev B