We investigate systematically the influence of the nature of thiol-type capping ligands on the optical and structural properties of highly luminescent CdTe quantum dots synthesized in aqueous media, comparing mercaptopropionic acid (MPA), thioglycolic acid (TGA), 1-thioglycerol (TGH), and glutathione (GSH). The growth rate, size distribution, and quantum yield strongly depend on the type of surface ligand used. While TGH binds too strongly to the nanocrystal surface inhibiting growth, the use of GSH results in the fastest growth kinetics. TGA and MPA show intermediate growth kinetics, but MPA yields a much lower initial size distribution than TGA. The obtained fluorescence quantum yields range from 38% to 73%. XPS studies unambiguously put into evidence the formation of a CdS shell on the CdTe core due to the thermal decomposition of the capping ligands. This shell is thicker when GSH is used as ligand, as compared with TGA ligands.

Depth-dependent Fe spin structures of the remanent state in exchange-coupled Fe/$\mathrm{Mn}{\mathrm{F}}_2$ films have been probed using ${}^{57}\mathrm{Fe}$ conversion electron Mössbauer spectroscopy, both above and well below the $\mathrm{Mn}{\mathrm{F}}_2$ Néel temperature. ${}^{57}\mathrm{Fe}$ probe layers were embedded either at the Fe/$\mathrm{Mn}{\mathrm{F}}_2$ interface or in the center of the Fe film. Remarkably, exchange bias induces a significant change of the in-plane angular distribution of the Fe magnetic moments at the interface and inside the Fe film, away from the saturation magnetization direction. Results from vector magnetometry support these conclusions.

The intermetallic antiferromagnetic compound Mn₂Au has been attracting considerable interest for antiferromagnetic spintronics due to its high Néel temperature and strong spin–orbit coupling. We report on the experimental investigation of the zero-wave number magnon frequencies in Mn₂Au films using Brillouin and Raman inelastic light scattering techniques. The derived effective anisotropy field values are in close agreement with theoretical calculations. With the values of the anisotropy and exchange fields, the full magnon dispersion curves in Mn₂Au were calculated. Due to the weak in-plane anisotropy, the k ∼ 0 frequency of the lower magnon branch, 121 GHz, is among the lowest for 3D antiferromagnets, suggesting that Mn₂Au is a good candidate for realizing the generation of spin currents by antiferromagnetic resonance driven spin-pumping, as proposed theoretically.

In this work, we report on a single-pot synthesis route based on a polymeric precursor method used for successfully producing undoped and iron-doped CeO₂ nanoparticles with iron contents up to 10.0 mol. %. The formation of high-crystalline nanoparticles with a cubic fluorite structure is determined for all the studied samples. Meanwhile, the magnetic measurements of the undoped ceria nanoparticles revealed the occurrence of ferromagnetism of bound magnetic polarons of a fraction of Ce³⁺ at room temperature, and only a paramagnetic behavior of Fe³⁺ ions was determined for Fe-doped ceria nanoparticles. A monotonous reduction of the effective magnetic moment of the Fe³⁺ ions was determined. It suggests a change from a high-spin to low-spin state of Fe ions as the Fe content is increased. The 3+ valence state of the iron ions has been confirmed by the Fe K-edge X-ray absorption near-edge structure (XANES) and Mössbauer spectroscopy measurements. X-ray photoelectron spectroscopy data analysis evidenced a coexistence of Ce³⁺ and Ce⁴⁺ ions and a decreasing tendency of the relative fraction of Ce³⁺ ions in the surface region of the particles as the iron content is increased. Although the coexistence of Ce³⁺ and Ce⁴⁺ is confirmed by results obtained via Ce L₃-edge XANES measurements, any clear dependence of the relative relation of Ce³⁺ ions on the iron content is determined, suggesting a homogeneous distribution of Ce³⁺ and Ce⁴⁺-ions in the whole volume of the particles. Ce L₃-edge extended X-ray absorption fine structure revealed that the Ce-O bond distance shows a monotonous decrease as the Fe content is increased, which is in good agreement with the shrinking of the unit cell volume with the iron content determined from XRD data analysis, reinforcing the substitutional solution of Ce and Fe ions in the CeO₂ matrix.