SPECTRAL REFLECTANCE VARIABLE ALLOY AND RECORDING MATERIAL

PURPOSE:To enable the adaptation to a material capable of recording and erasing information, by preparing an alloy, which takes different spectral reflectances on the basis of the change in a crystal structure by quenching and heating, by compounding Cu and Sn being main components in a specific ratio. CONSTITUTION:A Cu-Sn alloy containing 16-35wt% of Sn is formed in a foil shape. This foil shows a golden color and changes to a silver white color upon heating and air-cooling. When this silver white substrate is scanned by laser beam, a golden color line can be drawn on the silver white substrate. When this line part is irradiated with low output laser beam, the golden color changes to the original silver white color. That is, this alloy has different crystal structures and spectral reflectances between first temp. higher than room temp. and second temp. lower than room temp. This change in the reflectance can be discriminated in a wavelength range excepting the vicinity of about 540nm. The recording material utilizing this alloy is enabled in the recording and erasion of information and the operation thereof can be performed repeatedly.