51 research outputs found
Thermoelectric properties of Pr3Rh4Sn13-type Yb3Co4Ge13 and Yb3Co4Sn13 compounds
Crystallographic data and thermoelectric properties (from 240 K up to 380 K)
of Yb3Co4Ge13, Yb3Co4Sn13 compounds and Yb2CeCo4Ge13 and Yb2.3La0.7Co4Ge13
solid solutions are reported. The Seebeck coefficients, electric resistance and
thermal conductivity increase monotonically with increasing temperature from
240 to 380 K for all the compounds. The Seebeck coefficient is S = 14 - 27 \mu
V//K for Yb3Co4Sn13, and S = -21 -- -12 \mu V/K for Yb3Co4Ge13. The
substitution of Yb for cerium or lanthanum in Yb3Co4Ge13 shifts the Seeebeck
coefficient to positive values. The Yb3Co4Sn13 has a maximal ZT parameter from
available Pr3Rh4Sn13-type compounds. The ZT parameter of Yb3Co4Sn13 compound
increases from 0.006 up to 0.017 with increasing temperature from 240 K to 380
K.Comment: 9 pages, pdf, final version, accepted to Journal of Alloys and
Compound
Non-Centrosymmetric Heavy-Fermion Superconductors
In this chapter we discuss the physical properties of a particular family of
non-centrosymmetric superconductors belonging to the class heavy-fermion
compounds. This group includes the ferromagnet UIr and the antiferromagnets
CeRhSi3, CeIrSi3, CeCoGe3, CeIrGe3 and CePt3Si, of which all but CePt3Si become
superconducting only under pressure. Each of these superconductors has
intriguing and interesting properties. We first analyze CePt3Si, then review
CeRhSi3, CeIrSi3, CeCoGe3 and CeIrGe3, which are very similar to each other in
their magnetic and electrical properties, and finally discuss UIr. For each
material we discuss the crystal structure, magnetic order, occurrence of
superconductivity, phase diagram, characteristic parameters, superconducting
properties and pairing states. We present an overview of the similarities and
differences between all these six compounds at the end.Comment: To appear in "Non-Centrosymmetric Superconductors: Introduction and
Overview", Lecture Notes in Physics 847, edited by E. Bauer and M. Sigrist
(Springer-Verlag, Berlin Heidelberg, 2012) Chap. 2, pp. 35-7
Magnetic structure of the NaCl-type NdSb compound
International audienceNeutron powder diffraction experiments have been carried out on the well-known NaCl-type polycrystalline NdSb compound. The neutron diffraction data obtained in zero field at 2 K, reveal commensurate antiferromagnetic ordering with magnetic moments of Nd directed along Z axis (M(Nd) = 3.1(1) mu(B)). Thermal variation of intensity of (001) magnetic reflection shows the temperature of magnetic ordering at T(N) = 13 K
Mo2NiB2-type {Gd, Tb, Dy)2Ni2.35Si0.65 and La2Ni3-type {Dy, Ho}2Ni2.5Si0.5 compounds: Crystal structure and magnetic properties
International audienc
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