MXenes are of great practical interest. While the physical properties of such a well-known MAX phase as Ti₃AlC₂ and the Ti₃C₂ MXene that is based on it have been widely studied, it is extremely important to study the properties of new four-component MAX-phases and the MXenes based on them. To do this, first, it is necessary to characterize the obtained materials. In this work, the Ti_3−xNb_xC₂ MXene was characterized. Since the material is fairly new, there are no crystallographic data for such systems in the international databases. We proposed a method for the determination of the main unit cell parameters of the new Ti_3−xNb_xC₂ MXene, which was based on a combination of the DFT method, TEM studies, and an X-ray diffraction analysis.

The present work reports on the experimental structures, and optoelectronic and luminescence properties of a series of low-dimensional hybrid organic–inorganic (1,5-pentanediamine)PbX ₄ (X = Cl, Br, I) perovskites.