The invention discloses small-particle yellow rare-earth fluorescent
powder and a preparation method and a purpose of visualizing a
latent fingerprint thereof. The general structure formula of the fluorescent
powder is Y3-x-yCexGdyA15O12, wherein the x is not less than 0.1 and no larger than 0.4, y is no less than 0.1 and no larger than 0.4 and the particle size is between 1.5 to 3 Mum. The preparation method comprises the steps of weighing up raw materials according to the stoichiometric ratio of the structure formula,
grinding and evenly mixing up the raw materials,
sintering the raw materials with high-temperature
solid-
phase method to obtain
powder and obtaining the small-particle yellow rare-earth fluorescent powder by adopting an
ultrasonic dispersion technology after the powder goes through a mesh with 300 to 400 eyes. The small-particle yellow rare-earth fluorescent powder can be applied to visualizing the latent
finger print after being amido-functionalized by gamma-Aminopropyl triethoxy
silane and being mixed with reduced
iron powder which goes through a mesh according to a certain ratio. The fluorescent powder provided by the invention has even and
small particles, high fluorescent intensity, the excitation wave length between 460 to 480nm which is within the range of the
light source commonly used in criminal investigation and the emission wave length between 520 to 570nm, is conducive to visualizing the latent
finger print on the site and eliminating the disturbance of the object background and is important for establishing a high-efficient, non-toxic, lossless and convenient
finger print visualizing method.