ALLOY HAVING VARIABLE SPECTRAL REFLECTANCE AND RECORDING MATERIAL

摘要

PURPOSE:To obtain a novel recording material applying a variable change of color or reflectance by transition between crystal structures by using an Au alloy contg. a specified amount of Cd and having variable spectral reflectance. CONSTITUTION:This alloy having variable spectral reflectance is an Au alloy contg. 40-60wt% Cd and having different crystal structures at the 1st temp. above room temp. and the 2nd temp. below the 1st temp. in the state of a solid soln. When part of the surface of the alloy is rapidly cooled from the 1st temp., the part has a crystal structure different from the crystal structure at the 2nd temp. The other part has the crystal structure at the 2nd temp. and is different from the rapidly cooled part in spectral reflectance. A novel recording material is made of the alloy having variable spectral reflectance.