Quantum Critical Behavior in the Heavy Fermion Single Crystal Ce(Ni0.935Pd0.065)2Ge2

Conference · Sat Jan 01 04:00:00 EST 2011

OSTI ID:1010991

Wang, Cuihuan ^[1]; Lawrence, J M ^[2]; Christianson, Andrew D ^[1]; Chang, S ^[3]; Bauer, E D ^[4]; Gofryk, K ^[4]; Ronning, F ^[4]; Thompson, J D ^[4]; McClellan, K J ^[4]; Rodriguez-Rivera, J A ^[5]; Lynn, J W ^[3]

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1. ORNL
2. University of California, Irvine
3. NIST Center for Neutron Research (NCRN), Gaithersburg, MD
4. Los Alamos National Laboratory (LANL)
5. NCNR and University of Maryland

We have performed magnetic susceptibility, specific heat, resistivity, and inelastic neutron scattering measurements on a single crystal of the heavy Fermion compound Ce(Ni{sub 0.935}Pd{sup 0.065}){sub 2}Ge{sub 2}, which is believed to be close to a quantum critical point (QCP) at T = 0. At lowest temperature (1.8--3.5 K), the magnetic susceptibility behaves as {chi}(T)-{chi} (0) {proportional_to} T{sup -1/6} with {chi} (0) = 0.032 x 10{sup -6} m{sup 3}/mole (0.0025 emu/mole). For T < 1 K, the specific heat can be fit to the formula {Delta} C/T = {gamma}{sub 0} - T{sup 1/2} with {gamma}{sub 0} of order 700 mJ/mole-K{sup 2}. The resistivity behaves as {rho} = {rho}{sub 0} + AT{sup 3/2} for temperatures below 2 K. This low temperature behavior for {gamma} (T) and {rho} (T) is in accord with the SCR theory of Moriya and Takimoto. The inelastic neutron scattering spectra show a broad peak near 1.5 meV that appears to be independent of Q; we interpret this as Kondo scattering with T{sub K} = 17 K. In addition, the scattering is enhanced near Q=(1/2, 1/2, 0) with maximum scattering at {Delta} E = 0.45 meV{sup -}; we interpret this as scattering from antiferromagnetic fluctuations near the antiferromagnetic QCP.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Flux Isotope Reactor
• Sponsoring Organization: ORNL LDRD Director's R&D
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1010991
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTIFERROMAGNETISM
CERIUM COMPOUNDS
ELECTRONS
FERMIONS
FLUCTUATIONS
GERMANIUM COMPOUNDS
INELASTIC SCATTERING
MAGNETIC SUSCEPTIBILITY
MONOCRYSTALS
NICKEL COMPOUNDS
PALLADIUM COMPOUNDS
SPECIFIC HEAT
SPECTRA