CePt3Si is a novel heavy fermion superconductor, crystallizing in the CePt3B structure as a tetragonally distorted low symmetry variant of the AuCu3 structure type. CePt3Si exhibits antiferromagnetic order at T(N) approximately 2.2 K and enters into a heavy fermion superconducting state at T(c) approximately 0.75 K. Large values of H(')(c2) approximately -8.5 T/K and H(c2)(0) approximately 5 T refer to heavy quasiparticles forming Cooper pairs. Hitherto, CePt3Si is the first heavy fermion superconductor without a center of symmetry.
Thermal conductivity of superconducting MgB 2 was studied in both the superconducting and the normal state region. The latter is almost equally determined by the electronic -and the lattice contribution to the total thermal conductivity. In the superconducting state, however, the lattice contribution is larger. The electronic thermal conductivity below T c was derived from the experimental data considering the Bardeen-Rickayzen-Tewordt theory together with the model of Geilikman. The analysis shows that electron scattering on static imperfections dominates.
Various concentrations of the solid solution
Yb2Pd2In1−xSnx ranging from
x = 0 to 1 with
the tetragonal Mo2FeB2-type structure were prepared and their physical properties were studied by means of bulk
and spectroscopic measurements as a function of temperature, pressure and magnetic fields.
Results deduced from these studies indicate a slight variation of the valency of the Yb ions,
from for both border compounds to
ν = 3 at
x = 0.6. This
variation gives rise to the appearance of long range magnetic order in a narrow concentration region
around x = 0.6, while both border compounds remain non-magnetic. The outstanding concentration
dependence for the ordered regime may be indicative of two quantum critical points, a
novel feature not yet observed in Yb compounds.
Transport and magnetic properties are reported for ternary skutterudites La 0.83 Fe 4 Sb 12 and Pr 0.73 Fe 4 Sb 12 . Physical properties of Pr 0.73 Fe 4 Sb 12 are dominated by crystal electric field effects, yielding in the magnetic triplet ⌫ 5 as ground state. As a result, long-range magnetic order appears below 4.6 K. Pr 0.73 Fe 4 Sb 12 exhibits an unusually high electronic contribution to the specific heat C p /T of several hundred mJ/mol K 2 , and a significant value of a nuclear Schottky contribution is derived below about 1 K, primarily related to 141 Pr with a nuclear spin Iϭ5/2. The figure of merit at room temperature, expressing the thermoelectric performance of Pr 0.73 Fe 4 Sb 12 , is about 0.075.
Eu 0.83 Fe 4 Sb 12 , was synthesized by arc melting in homogeneous practically single phase form. From Rietveld refinement isotypism was derived with the LaFe 4 P 12 -͑skutterudite͒-type, space group Im 3 , No. 204. The refinement also served to determine the Eu content of xϭ0.83(2). Eu 0.83 Fe 4 Sb 12 orders magnetically below 84 K and isothermal magnetization measurements reveal a spontaneous magnetization reaching about 4.5 B /f.u. at 6 T. The electronic configuration of the Eu ion in this compound appears to be close to the 4 f 7 state, thus behaving almost divalently. From the measurements of transport coefficients, the figure of merit Z was evaluated as ZTϷ0.08 at room temperature. The most outstanding property of this compound, however, is the significant magnetoresistance of about 130% at Tϭ1 K for a magnetic field of 12 T but still 30% near room temperature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.