METHOD OF PROTECTING FROM FORGERY AND CHECKING AUTHENTICITY OF VALUABLE ARTICLES Russian patent published in 2010 - IPC G07D7/06 

FIELD: physics.

SUBSTANCE: invention can be used to protect museum valuables from forgery, as well as expensive medicinal agents, intellectual property, bond paper, and for facilitating their subsequent authentication using equipment. A protective element with a given structure is formed on the valuable article, which enables checking for presence and authenticity of the said element using a physical analysis method based on magnetic effects and detection of information features in the response of the protective element using an external magnetic field. The detected information feature used is the effect of "giant" change in magnetic resistance of the protective element, and the protective element used is a film consisting of either alternating layers of magnetic and non-magnetic material with nanosized thickness or single-domain ferromagnetic particles with nanosized thickness with a randomly directed magnetisation vector, where the particles are in a magnetic matrix, or substance with a crystalline structure LaMnO₃ in which La is replaced with Ca or Sr during doping.

EFFECT: guaranteed protection of valuable articles from forgery and possibility of their authentication using simple equipment.

8 dwg