Abstract: The present invention relates to a security marker; a method of preparing same; the use of said security marker; a security article, document, or element comprising said marker; the use of said security article, document, or element; an object of value comprising said marker; a method of preparing said security article, document, or element or said object of value; a method for determining the authenticity of said security article, document, or element or said object of value; and a system for determining the authenticity of said security article, document, or element or said object of value.

Abstract: The present invention relates to a nanostructured phosphorescent pigment comprising an Al2O3 substrate; MAl2O4:X nanocrystals, where M is a cation selected from Ca2+, Sr2+, Ba2+, Mg2+, Zn3+ and combinations thereof and where X is a cation selected from Eu3+, Dy3+, Nd3+, Er3+, La3+, Lu3+, Ce3+, Y3+, Gd3+, Tb3+, Tm3+, Yb3+ and combinations thereof, disposed on the Al2O3 substrate; and nanocrystals of molten salt disposed on the MAl2O4:X nanocrystals. Additionally, the invention relates to a method for preparing the nanostructured phosphorescent pigment of the invention comprising the steps of i) mixing starting materials comprising a cation M precursor, a cation X precursor, Al2O3 and a molten salt; ii) heating the mixture resulting from step (i) in reducing atmosphere.

Abstract: The present invention relates to a nanostructured phosphorescent pigment comprising an Al2O3 substrate; MAl2O4:X nanocrystals, where M is a cation selected from Ca2+, Sr2+, Ba2+, Mg2+, Zn2+ and combinations thereof and where X is a cation selected from Eu2+, Dy3+, Nd3+, Er3+, La3+, Lu3+, Ce3+, Y3+, Sm3+, Gd3+, Tb3+, Tm3+, Yb3+ and combinations thereof, disposed on the Al2O3 substrate; and nanocrystals of molten salt disposed on the MAl2O4:X nanocrystals. Additionally, the invention relates to a method for preparing the nanostructured phosphorescent pigment of the invention comprising the steps of i) mixing starting materials comprising a cation M precursor, a cation X precursor, Al2O3 and a molten salt; ii) heating the mixture resulting from step (i) in reducing atmosphere.

Abstract: The process is characterised in that it comprises at least one sol-gel layer with a maximum thickness of 800 nm, where said sol-gel layer comprises nanoparticles with a laminar crystal structure, and where each sol-gel layer is obtained from a silicon alkoxide solution; preparation of a dispersion that comprises at least one type of particles with a spherical, fibrillar or laminar morphology, and a laminar crystal structure, wherein at least one of the dimensions, thickness or diameter, of said particles is less than 400 nm; addition of the dispersion prepared to the solution; deposition of the suspension on said substrate; thermal treatment of the substrate; and, in the case of multilayer coatings, optionally, the addition of high-dimensional particles and repetition of the steps, provided that the thermal treatment of the last layer, or outer layer, is performed at a temperature equal to or greater than that of the preceding layer. The invention also relates to the sol-gel coating thus obtained.