Half-metallic ferromagnetic materials with planar forms are promising for spintronics applications. A wide range of 2D lattices like graphene, h-BN, transition metal dichalcogenides, etc. are non-magnetic or weakly magnetic. Using first principles calculations, the existence of graphene-like hexagonal chromium nitride (h-CrN) with an almost flat atomically thin structure is predicted. We find that freestanding h-CrN has a 100% spin-polarized half-metallic nature with possible ferromagnetic ordering and a high rate of optical transparency. As a possible method for stabilization and synthesis, deposition of h-CrN on 2D MoSe₂ or on MoS₂ is proposed. The formation of composites retains the half-metallic properties and leads to the reduction of spin-down band gaps to 1.43 and 1.71 eV for energetically favorable h-CrN/MoSe₂ and h-CrN/MoS₂ configurations, respectively. Calculation of the dielectric functions of h-CrN, h-CrN/MoSe₂ and h-CrN/MoS₂ exhibit the high transparency of all three low-dimensional nanomaterials. The honeycomb CrN may be considered as a promising fundamental 2D material for a variety of potential applications of critical importance.

The absorption energy and diffusion rates of lithium atoms inside graphitelike boron carbide (BC3) crystal are investigated by the ab initio pseudopotential density-functional method using generalized gradient approximation. It is shown that lithium may effectively intercalate this structure with the maximum lithium concentration corresponding to Li2BC3 stoichiometry, which is threefold in comparison to lithium in graphite. The potential barrier values for lithium diffusion both at low and maximum concentration are about 0.19 eV, so lithium atoms inside the BC3 structure can move easily. These findings suggest that boron carbide looks like a good candidate as an anode material in lithium ion batteries.

Nanotechnologies involving physical methods of tumor destruction using functional oligonucleotides are promising for targeted cancer therapy. Our study presents magnetodynamic therapy for selective elimination of tumor cells in vivo using DNA aptamer-functionalized magnetic nanoparticles exposed to a low frequency alternating magnetic field. We developed an enhanced targeting approach of cancer cells with aptamers and arabinogalactan. Aptamers to fibronectin (AS-14) and heat shock cognate 71 kDa protein (AS-42) facilitated the delivery of the nanoparticles to Ehrlich carcinoma cells, and arabinogalactan (AG) promoted internalization through asialoglycoprotein receptors. Specific delivery of the aptamer-modified FeAG nanoparticles to the tumor site was confirmed by magnetic resonance imaging (MRI). After the following treatment with a low frequency alternating magnetic field, AS-FeAG caused cancer cell death in vitro and tumor reduction in vivo. Histological analyses showed mechanical disruption of tumor tissues, total necrosis, cell lysis, and disruption of the extracellular matrix. The enhanced targeted magnetic theranostics with the aptamer conjugated superparamagnetic ferroarabinogalactans opens up a new venue for making biocompatible contrasting agents for MRI imaging and performing non-invasive anti-cancer therapies with a deep penetrated magnetic field.

The magnetic properties of vacancies in 2D hexagonal structures—graphene and 2D-SiC and h-BN monolayers—have been studied. It has been found that a local magnetic moment exists in all listed systems in the presence of vacancies. However, in 2D hexagonal silicon carbide, the local magnetic moment appears only in the presence of silicon vacancy. In addition, the effect of the distance between vacancies in a monolayer on transitions between the ferromagnetic and antiferromagnetic states has been revealed.