Titanium nitride (TiN), with its tunable work function, serves as an electrode metal in the scaling fin-type field-effect transistor and plays the key role for low threshold operation. Measuring the effective work function of thin TiN films is desirable for rapid evaluation before device fabrication. In this work, Kelvin probe force microscopy is applied to study the impact of various factors on the surface potential of TiN films with an uncertainty below 30 mV. By scraping and gauging the potential evolvement of TiN in different circumstances, it is revealed that the surface effect is the major obstacle to determine the work function of the as-deposited TiN. For thick films, the potential drops over 530 mV for a fresh TiN surface relative to that of an aged one. For TiN films thinner than 5 nm, the potential changes by 290 mV due to surface oxidation. This enables a quantitative assessment on the effective work function as well as the surface charge density of TiN films.

The side effects of chemotherapy are mainly the poor control of drug release. Magnetic nanoparticles (MNPs) have super-paramagnetic behaviors which are preferred for biomedical applications such as in targeted drug delivery, besides, in magnetic recording, catalysis, and others. MNPs, due to high magnetization response, can be manipulated by the external magnetic fields to penetrate directly into the tumor, thus they can act as ideal drug carriers. MNPs also play a crucial role in drug delivery system because of their high surface-to-volume ratio and porosity. The drug delivery in tumor therapy is related to the sizes, shapes, and surface coatings of MNPs as carriers. Therefore, in this review, we first summarize the effects of the sizes, shapes, and surface coatings of MNPs on drug delivery, then discuss three types of drug release systems, i.e., pH-controlled, temperature-controlled, and magnetic-controlled drug release systems, and finally compare the principle of passive drug release with that of active drug release in tumor therapy.

Triple‐negative breast cancer (TNBC), one of the most aggressive types of breast cancer, currently lacks a targeted therapy and has a high clinical recurrence rate. The present study reports an engineered magnetic nanodrug based on Fe₃O₄ vortex nanorods coated with a macrophage membrane loaded with doxorubicin (DOX) and Enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) siRNA. This novel nanodrug displays excellent tissue penetration and preferential tumor accumulation. More importantly, it significantly increases tumor suppression compared to chemotherapy, suggesting the synergistic activity of the combination of doxorubicin and EZH2‐inhibition. Importantly, owing to tumor‐targeted delivery, nanomedicine shows an excellent safety profile after systemic delivery, unlike conventional chemotherapy. In summary, chemotherapy and gene therapy are combined into a novel magnetic nanodrug carrying doxorubicin and EZH2 siRNA, which shows promising clinical application potential in TNBC therapy.

Low-temperature phase (LTP) MnBi is considered as a promising rare-earth-free permanent magnetic material with high coercivity and unique positive temperature coefficient of coercivity. Mn₅₅Bi₄₅ ribbons with high purity of LTP MnBi phase were prepared by melt spinning. Then, Mn₅₅Bi₄₅ powders with different particle size were obtained by low-energy ball milling (LEBM) with and without added surfactant. The coercivity is enhanced in both cases. Microstructure characterization reveals that Mn₅₅Bi₄₅ powders obtained by surfactant assisted low-energy ball milling (SALEBM) have better particle size uniformity and show higher decomposition of LTP MnBi. Coercivity can achieve a value of 17.2 kOe and the saturation magnetization (M_s) is 16 emu/g when Mn₅₅Bi₄₅ powders milled about 10 h by SALEBM. Coercivity has achieved a maximum value of 18.2 kOe at room temperature, and 23.5 kOe at 380 K after 14 h of LEBM. Furthermore, Mn₅₅Bi₄₅ powders obtained by LEBM have better magnetic properties.