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Transport and thermodynamic properties were studied for the complex metallic compound $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Al}}_{3}{\mathrm{Mg}}_{2}$, composed of 925 atoms per unit cell. $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Al}}_{3}{\mathrm{Mg}}_{2}$ exhibits bulk superconductivity below ${T}_{c}=0.87\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. An exponential temperature dependence of the specific heat well below ${T}_{c}$ indicates BCS-like behavior with a nodeless gap of width ${\ensuremath{\Delta}}_{\mathit{BCS}}(0)\ensuremath{\approx}1.5\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The coherence length is derived as ${\ensuremath{\xi}}_{0}=4.85\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}\phantom{\rule{0.3em}{0ex}}\mathrm{m}$ and the Ginzburg Landau parameter ${\ensuremath{\kappa}}_{\mathrm{GL}}\ensuremath{\approx}13$, characterizing $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Al}}_{3}{\mathrm{Mg}}_{2}$ as a type II superconductor. Superconductivity in $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Al}}_{3}{\mathrm{Mg}}_{2}$ occurs in the absence of inversion symmetry of the crystal. Surprisingly, in spite of the rather complex crystal structure of $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Al}}_{3}{\mathrm{Mg}}_{2}$, physical properties turn out to be quite simple.

In order to understand the anisotropic magnetic and electrical properties of ternary compounds $\mathrm{Ce}T{\mathrm{Sb}}_{2}$ $(T=\mathrm{Cu},$ Au, Ni) with the tetragonal structure, we have grown single crystals of this series by the self-flux method and measured the electrical resistivity, magnetic susceptibility, magnetization, and specific heat. ${\mathrm{CeCuSb}}_{2}$ and ${\mathrm{CeAuSb}}_{2}$ are found to order antiferromagnetically with N\'eel temperatures of 6.9 K and 5.0 K, respectively, while ${\mathrm{CeNiSb}}_{2}$ is a ferromagnet with a Curie temperature of 6.0 K with an easy axis of magnetization oriented along the [100] direction. The magnetic property of ${\mathrm{CeCuSb}}_{2}$ shows a very small anisotropy, whereas the electrical resistivity is highly anisotropic between $J\ensuremath{\Vert}$ [100] and [001]. In contrast, ${\mathrm{CeAuSb}}_{2}$ and ${\mathrm{CeNiSb}}_{2}$ show a strong anisotropy both in the magnetic and electrical measurements, although the magnetic easy axis is interchanged with respect to each other. The anisotropy in the magnetic properties has been explained on the basis of a crystalline electric-field model.

Systematic neutron-scattering experiments have been carried out in order to reveal the crystal and magnetic structures as well as the magnetic excitation in the Ce-based intermetallic compound ${\mathrm{CeAgSb}}_{2}.$ It was clarified that the Ag atoms in ${\mathrm{CeAgSb}}_{2}$ (space group: $\mathrm{P}4/nmm)$ occupy the 2b site, while Sb atoms occupy $2a$ and $2c$ sites, which have, to date, been controversial in literature. From the analysis of neutron powder-diffraction profile, we found the existence of the ferromagnetic component of about $0.41{\ensuremath{\mu}}_{\mathrm{B}}/\mathrm{Ce}$ oriented along the c axis, consistent with the result of previous studies. On the other hand, however, no trace of the antiferromagnetic or spin-density wave peak was detected within our range of experimental accuracy. We observed a considerable spin-wave excitation below 3 meV. The dispersion relation was explained by the anisotropic Heisenberg model. This means that ${\mathrm{CeAgSb}}_{2}$ has a simple ferromagnetic structure. Furthermore, crystalline electric-field (CEF) excitations were observed at 5.2 and 12.5 meV in the paramagnetic state, which is indicative of the localized nature of the $\mathrm{Ce}\ensuremath{-}4f$ electron. Our analysis revealed that $|{J}_{z}=\ifmmode\pm\else\textpm\fi{}\frac{1}{2}〉$ is the ground state, while the first and second excited levels are mainly due to $|\ifmmode\pm\else\textpm\fi{}\frac{3}{2}〉$ and $|\ifmmode\pm\else\textpm\fi{}\frac{5}{2}〉,$ respectively. The observed ferromagnetic moment is in good agreement with the ground-state saturation moment, ${g}_{J}{\ensuremath{\mu}}_{\mathrm{B}}{J}_{\mathrm{z}}\ensuremath{\sim}0.43{\ensuremath{\mu}}_{\mathrm{B}}.$ The susceptibility, magnetization curve, and magnetostriction can be explained in terms of the CEF level scheme with anisotropic exchange interaction.

We have studied the thermal and magnetic properties of a single crystal of ${\mathrm{CeAgSb}}_{2},$ which has a small net magnetic moment of about $0.4{\ensuremath{\mu}}_{\mathrm{B}}$ below the ordering temperature ${T}_{\mathrm{ord}}=9.7\mathrm{K},$ by means of specific heat, thermal expansion, and magnetization measurements. The magnetic part of the specific heat shows a broad peak around 30 K, and the magnetic entropy reaches $R\mathrm{ln}4$ at about 50 K. This indicates that the first excited doublet is situated at about 50 K from the ground state. In addition, the thermal expansion along the tetragonal [001] direction exhibits a clear negative peak around 25 K, which is also attributed to the magnetic excitations between crystalline electric field (CEF) states. These data, together with the anisotropic magnetic susceptibility, were analyzed on the basis of a CEF model, and splitting energies from the ground state to the first and second excited states were estimated to be 48 and 140 K, respectively. Furthermore, the anisotropy in the high-field magnetization was well explained by the present CEF model with the same parameters, where the saturation moment for $H\ensuremath{\Vert}$ [001] is found to be determined by the value of ${g}_{J}{J}_{z}$ of the ground state.

We report on a series of structural, magnetic, and thermodynamic measurements, a study of transport properties and x-ray absorption edge spectroscopy on $\mathrm{Ce}({\mathrm{Rh}}_{1\ensuremath{-}x}{\mathrm{Ru}}_{x}{)}_{3}{\mathrm{B}}_{2}.$ These investigations evidence that in addition to the already established ferromagnetic range for $xl~0.06,$ a complex antiferromagnetic structure exists for concentrations $0.1l~xl~0.35.$ The behavior in the latter regime is dominated by an extraordinary strong intersite coupling; however, the magnetic moments involved appear to be very small. At the phase boundary to the paramagnetic regime $(x\ensuremath{\approx}0.4),$ significant deviations from a Fermi-liquid behavior occur.

Eu{sub 0.83}Fe{sub 4}Sb{sub 12}, was synthesized by arc melting in homogeneous practically single phase form. From Rietveld refinement isotypism was derived with the LaFe{sub 4}P{sub 12}-(skutterudite)-type, space group Im{bar 3}, No. 204. The refinement also served to determine the Eu content of x=0.83(2). Eu{sub 0.83}Fe{sub 4}Sb{sub 12} orders magnetically below 84 K and isothermal magnetization measurements reveal a spontaneous magnetization reaching about 4.5{mu}{sub B}/f.u. at 6 T. The electronic configuration of the Eu ion in this compound appears to be close to the 4f{sup 7} state, thus behaving almost divalently. From the measurements of transport coefficients, the figure of merit Z was evaluated as ZT{approximately}0.08 at room temperature. The most outstanding property of this compound, however, is the significant magnetoresistance of about 130% at T=1 K for a magnetic field of 12 T but still 30% near room temperature.