1,555 research outputs found
Unusual Single-Ion Non-Fermi Liquid Behavior in Ce_(1-x)La_xNi_9Ge_4
We report on specific heat, magnetic susceptibility and resistivity
measurements on the compound Ce_(1-x)La_xNi_9Ge_4 for various concentrations
ranging from the stoichiometric system with x=0 to the dilute limit x=0.95. Our
data reveal single-ion scaling with the Ce-concentration and the largest ever
recorded value of the electronic specific heat c/T approximately 5.5 J
K^(-2)mol^(-1) at T=0.08K for the stoichiometric compound x=0 without any trace
of magnetic order. While in the doped samples c/T increases logarithmically
below 3K down to 50mK, their magnetic susceptibility behaves Fermi liquid like
below 1K. These properties make the compound Ce_(1-x)La_xNi_9Ge_4 a unique
system on the borderline between Fermi liquid and non-Fermi liquid physics.Comment: 4 pages, 5 figures; v2 contains additional resisitivity measurements;
final version to appear in Phys. Rev. Let
Low temperature magnetic phase diagram of the cubic non-Fermi liquid system CeIn_(3-x)Sn_x
In this paper we report a comprehensive study of the magnetic susceptibility
(\chi), resistivity (\rho), and specific heat (C_P), down to 0.5 K of the cubic
CeIn_(3-x)Sn_x alloy. The ground state of this system evolves from
antiferromagnetic (AF) in CeIn_3(T_N=10.2 K) to intermediate-valent in CeSn_3,
and represents the first example of a Ce-lattice cubic non-Fermi liquid (NFL)
system where T_N(x) can be traced down to T=0 over more than a decade of
temperature. Our results indicate that the disappearance of the AF state occurs
near x_c ~ 0.7, although already at x ~ 0.4 significant modifications of the
magnetic ground state are observed. Between these concentrations, clear NFL
signatures are observed, such as \rho(T)\approx \rho_0 + A T^n (with n<1.5) and
C_P(T)\propto -T ln(T) dependencies. Within the ordered phase a first order
phase transition occurs for 0.25 < x < 0.5. With larger Sn doping, different
weak \rho(T) dependencies are observed at low temperatures between x=1 and x=3
while C_P/T shows only a weak temperature dependence.Comment: 7 pages, 7 figures. Accepted in Eur. J. Phys.
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