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MA: Fachverband Magnetismus

MA 17: Magnetic Particles and Clusters (jointly with CPP, BP)

MA 17.1: Hauptvortrag

Dienstag, 12. März 2013, 09:30–10:00, H22

Magnetometry to identify the origin of printed documents — •Anna S. Semisalova, Vladimir N. Nikiforov, and Nikolai S. Perov — Lomonosov Moscow State University, Faculty of Physics, Moscow, Russia

Counterfeiting of valuable documents is an increasingly serious problem. For example, diplomas and stock certificates are all the subjects of increasingly frequent and accurate counterfeiting efforts. Identification of the true source of printed documents is a challenging task [1]. Many methods such as chemical analysis, various types of spectroscopy and microscopy, require a special sample preparation which may lead to the destruction of parts of the documents. Magnetometry may provide a non-destructive technique to uniquely identify the source of documents printed by using inks or toners containing magnetic particles.

Here, we will present an overview of the magnetic properties of documents produced by different laser printers (Canon, HP, Lexmark, Kyocera). The magnetic behavior of laser printers toners were investigated by vibrating sample magnetometry. Magnetic parameters such as coercive field and magnetic moment were measured, compared and are shown to be a possible source for classification, differentiation and identification of toner powders. The investigation of magnetic properties of toners could be considered as a new surprisingly simple non-destructive approach to certify and identify certain printers, since the printer toners were found to vary with manufacturer. The practical applications for counterfeit analysis are discussed. 1. Scientific Examination of Questioned Documents, ed. by Kelly J.S., 2006.