Model of bidirectional reflectance distribution function for metallic materials
Wang Kai1, Zhu Jing-Ping1, †, 
, Liu Hong1, 2, Hou Xun1
, Liu Hong1, 2, Hou Xun1 (a) Piezoresponse force microscope and (b) metallic materials: Al (left) with different roughness, Cu (middle) and Fe (right).
