TY - JOUR
T1 - Magnetic short-range correlations and quantum critical scattering in the non-Fermi liquid regime of URu2-x Rex Si2 (x=0.2-0.6)
AU - Krishnamurthy, V. V.
AU - Adroja, D. T.
AU - Butch, N. P.
AU - Sinha, S. K.
AU - Maple, M. B.
AU - Osborn, R.
AU - Robertson, J. L.
AU - Nagler, S. E.
AU - Aronson, M. C.
PY - 2008/7/16
Y1 - 2008/7/16
N2 - The spin dynamics of uranium ions in the non-Fermi liquid compounds URu2-x Rex Si2, for x=0.2 to 0.6, have been investigated using inelastic neutron scattering. The wave vector (q) dependence of the magnetic scattering provides evidence of short-range antiferromagnetic correlations at low temperatures for x=0.2,0.25, but the scattering is nearly q independent at x=0.35,0.6. The magnetic response, S̄ (ω), obtained from the q -independent part of neutron scattering, varies as ω-α with a composition-dependent exponent α=0.2-0.5. The dynamic magnetic susceptibility χ″ (q,ω) of the q -independent part exhibits ω/T scaling for the energy transfer ω between 3.5 and 17 meV in the temperature (T) range of 5-300 K at all the compositions. This scaling, which indicates local quantum criticality, breaks down in the q range, 0.6-1.1 Å-1 at x=0.2 and 0.25, that is dominated by short-range antiferromagnetic correlations. The appearance of power laws in the magnetic response measured by inelastic neutron scattering over a wide Re doping region indicates a disorder driven non-Fermi liquid mechanism for the low-temperature physical properties in these compounds.
AB - The spin dynamics of uranium ions in the non-Fermi liquid compounds URu2-x Rex Si2, for x=0.2 to 0.6, have been investigated using inelastic neutron scattering. The wave vector (q) dependence of the magnetic scattering provides evidence of short-range antiferromagnetic correlations at low temperatures for x=0.2,0.25, but the scattering is nearly q independent at x=0.35,0.6. The magnetic response, S̄ (ω), obtained from the q -independent part of neutron scattering, varies as ω-α with a composition-dependent exponent α=0.2-0.5. The dynamic magnetic susceptibility χ″ (q,ω) of the q -independent part exhibits ω/T scaling for the energy transfer ω between 3.5 and 17 meV in the temperature (T) range of 5-300 K at all the compositions. This scaling, which indicates local quantum criticality, breaks down in the q range, 0.6-1.1 Å-1 at x=0.2 and 0.25, that is dominated by short-range antiferromagnetic correlations. The appearance of power laws in the magnetic response measured by inelastic neutron scattering over a wide Re doping region indicates a disorder driven non-Fermi liquid mechanism for the low-temperature physical properties in these compounds.
UR - http://www.scopus.com/inward/record.url?scp=47949105565&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.78.024413
DO - 10.1103/PhysRevB.78.024413
M3 - Article
AN - SCOPUS:47949105565
SN - 1098-0121
VL - 78
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 2
M1 - 024413
ER -