Dopamine-based attachment chemistry was used to form trifunctional magnetic particles.

The exhaust of power and particles is regarded as a major challenge in view of the design of a magnetic confinement nuclear fusion demonstration power plant (DEMO). In such a reactor, highly loaded plasma facing components (PFCs), like the divertor targets, have to withstand both severe heat flux loads and considerable neutron irradiation. Existing divertor target designs make use of monolithic tungsten (W) and copper (Cu) material grades that are combined in a PFC. Such an approach, however, bears engineering difficulties as W and Cu are materials with inherently different thermomechanical properties and their optimum operating temperature windows do not overlap. Against this background, W?Cu composite materials are promising candidates regarding the application to the heat sink of highly loaded PFCs. The present contribution summarises recent results regarding the manufacturing and characterisation of such W?Cu composite materials produced by means of liquid Cu melt infiltration of open porous W preforms. On the one hand, this includes composites manufactured by infiltrating powder metallurgically produced W skeletons. On the other hand, W?Cu composites based on textile technologically produced fibrous reinforcement preforms are discussed

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 Néel 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 $J\Vert$ [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.

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 $0.4{\mu }_{\mathrm{B}}$ below the ordering temperature $T_{\mathrm{ord}}=9.7\mathrm{}\mathrm{K},$ 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 $R\ln 4$ 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 $H\Vert$ [001] is found to be determined by the value of $g_J{J}_z$ of the ground state.

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 $0.41{\mu }_{\mathrm{B}}/\mathrm{Ce}$ 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 $\mathrm{Ce}-4f$ electron. Our analysis revealed that $|J_z=\pm \frac{1}{2}〉$ is the ground state, while the first and second excited levels are mainly due to $|\pm \frac{3}{2}〉$ and $|\pm \frac{5}{2}〉,$ respectively. The observed ferromagnetic moment is in good agreement with the ground-state saturation moment, $g_J{\mu }_{\mathrm{B}}{J}_{\mathrm{z}}\sim 0.43{\mu }_{\mathrm{B}}.$ The susceptibility, magnetization curve, and magnetostriction can be explained in terms of the CEF level scheme with anisotropic exchange interaction.