简介:Above image is a copper sample coated with nickel and gold. Since nickel and copper have similar atomic number, it is hard to differentiate the boundary between the two. Through chemical etching, as shown in the right im简介:Above image is a copper sample coated with nickel and gold. Since nickel and copper have similar atomic number, it is hard to differentiate the boundary between the two. Through chemical etching, as shown in the right image, two layers can be easily distinguished. If etching is impossible, layers can be distinguished in the BSE mode.详细>