The intermetallic phases brass (Cu/Zn) and bronze (Cu/Sn) are corroded by a
mmonium fluoride and chloride, NH4F and NH4Cl, through selective oxidation
of the less noble component zinc and tin, respectively. Copper is recrystal
lized as cube-like or tabular single crystals under the respective influenc
e of fluoride and chloride. Zinc and tin are incorporated in complex compou
nds of which (Nn(4))ZnF3, (NH4)(2)ZnF4, Zn(NH3)(2)Cl-2 and (NH4)(3)SnF7 wer
e detected by X-ray powder diffraction.