Magnetic Fe3O4 nanoparticles (NPs) and their surface modification with therapeutic substances are of great interest, especially drug delivery for cancer therapy, including boron-neutron capture therapy (BNCT). In this paper, we present the results of boron-rich compound (carborane borate) attachment to previously aminated by (3-aminopropyl)-trimethoxysilane (APTMS) iron oxide NPs. Fourier transform infrared spectroscopy with Attenuated total reflectance accessory (ATR-FTIR) and energy-dispersive X-ray analysis confirmed the change of the element content of NPs after modification and formation of new bonds between Fe3O4 NPs and the attached molecules. Transmission (TEM) and scanning electron microscopy (SEM) showed Fe3O4 NPs’ average size of 18.9 nm. Phase parameters were studied by powder X-ray diffraction (XRD), and the magnetic behavior of Fe3O4 NPs was elucidated by Mössbauer spectroscopy. The colloidal and chemical stability of NPs was studied using simulated body fluid (phosphate buffer—PBS). Modified NPs have shown excellent stability in PBS (pH = 7.4), characterized by XRD, Mössbauer spectroscopy, and dynamic light scattering (DLS). Biocompatibility was evaluated in-vitro using cultured mouse embryonic fibroblasts (MEFs). The results show us an increasing of IC50 from 0.110 mg/mL for Fe3O4 NPs to 0.405 mg/mL for Fe3O4-Carborane NPs. The obtained data confirm the biocompatibility and stability of synthesized NPs and the potential to use them in BNCT.

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NiFe nanocrystalline films were formed onto Au film via pulsed electrolyte deposition with variable time of relaxation between the sequential pulses. Analysis of anomalous non-liner changes in the NiFe film structure showed the implementation of three mechanisms, resulting in "layer-by-layer", "layer-plus-island", or "island" growth. The change of the interpulse relaxation time provides the possibility to realize all three different mechanisms. The grown NiFe films may have different morphology. The ultrathin NiFe films have nanosized grains and exhibit high uniformity of structure, the films may be also combined of less that 10 nm nanoscale grains and their conglomerates, typically, about 50 nm in size, and, additionally, the film structure, consisting of isolated magnetic islands can be realized. The phenomenological explanation of the different mechanisms was obtained using atomic-force-microscopy (AFM) approach. It has been demonstrated that the growth mechanism can be controlled by nanocrystallites conglomeration, which is accelerated with increasing the relaxation time. The origin of the conglomeration process is mainly associated with high surface energy of nanosized grains.

The effect of treatment conditions on the magnetic and magnetotransport properties of A-site ordered PrBaMn2O6−δ manganites is examined. The parent oxygen-stoichiometric A-site ordered PrBaMn2O6 samples were prepared from oxygen-stoichiometric A-site disordered Pr0.50Ba0.50MnO3 ones by using a ‘two-step’ synthesis method. The most significant structural feature of the A-site ordered manganites is that the MnO2 sublattice is sandwiched by two kinds of rock-salt layers, PrOx and BaO. The oxygen-stoichiometric A-site ordered PrBaMn2O6 demonstrates a ferromagnetic metal to paramagnetic insulator transition with the Curie point at about 320 K. These compounds are stable in air up to 1300 °C. The A-site ordered PrBaMn2O6 samples were next reduced in flowing argon as well as being treated under high pressure conditions. The reduction of the A-site ordered PrBaMn2O6 samples leads to the appearance of an antiferromagnetic state with a Néel point of about 140 K, while the A-site order remains. Upon high pressure treatment the degree of A-site order decreases, which reduces TC to 180 K. The magnetotransport properties of A-site ordered manganites treated under different conditions are discussed in terms of the manganese valence, oxygen content and degree of A-site order.