CoFe(2)O(4) nanoparticles (D(NPD) ~6 nm), prepared by a thermal decomposition technique, have been investigated through the combined use of dc magnetization measurements, neutron diffraction, and (57)Fe Mössbauer spectrometry under high applied magnetic field. Despite the small particle size, the value of saturation magnetization at 300 K (M(s) ͠= 70 A m(2) kg(-1)) and at 5 K (M(s) ͠= 100 A m(2) kg(-1)) are rather close to the bulk values, making the samples prepared with this method attractive for biomedical applications. Neutron diffraction measurements indicate the typical ferrimagnetic structure of the ferrites, showing an inversion degree (γ(NPD) = 0.74) that is in very good agreement with cationic distribution established from low temperature (10 K) Mössbauer measurements in high magnetic field (γ(moss) = 0.76). In addition, the in-field Mössbauer spectrum shows the presence of a non-collinear spin structure in both A and B sublattices. The results allow us to explain the high value of saturation magnetization and provide a better insight into the complex interplay between cationic distribution and magnetic disorder in ferrimagnetic nanoparticles.

Alginate is a naturally occurring polysaccharide commonly derived from brown algae cell walls which possesses unique features that make it extremely promising for several biomedical and pharmaceutical purposes. Alginate biomaterials are indeed nowadays gaining increasing interest in drug delivery and tissue engineering applications owing to their intrinsic biocompatibility, non‐toxicity, versatility, low cost, and ease of functionalization. Specifically, alginate‐based nanostructures show enhanced capabilities with respect to alginate bulk materials in the targeted delivery of drugs and chemotherapies, as well as in helping tissue reparation and regeneration. Hence, it is not surprising that the number of scientific reports related to this topic have rapidly grown in the last decade. With these premises, the present review aims to provide a comprehensive state‐of‐the‐art of the most recent advances in the preparation of alginate‐based nanoparticles and electrospun nanofibers for drug delivery, cancer therapy, and tissue engineering purposes. After a short introduction concerning the general properties and uses of alginate and the concept of nanotechnology, the recent literature is then critically presented to highlight the main advantages of alginate‐based nanostructures. Finally, the current limitations and the future perspectives and objectives are discussed in detail.

We measure magnetotransport of F-doped SmFeAsO samples up to 28 T and we extract the upper critical fields, using different criteria. In order to circumvent the problem of criterion-dependent $H_{c2}$ values, we suggest a thermodynamic estimation of the upper critical field slope $d{H}_{c2}/dT$ based on the analysis of conductivity fluctuations in the critical regime. A high field slope as large as $-12\text{T}/\text{K}$ is thus extracted for the optimally doped sample. We find evidence of a two-dimensional lowest Landau level (LLL) scaling for applied fields larger than ${\mu }_0{H}_{\text{LLL}}\sim 8\text{T}$. Finally, we estimate the coherence length values and we observe that they progressively increase with decreasing $T_c$. In all cases, the coherence length values along the $c$ axis are smaller than the interplanar distance, confirming the two-dimensional nature of superconductivity in this compound.