Electron-diffraction technique has been used to study the modification of surface structure of silver electrodeposits deposited from the argentocyanide bath in presence of addition agents such as carbon disulphide, thiosemicarbazide, thiourea, and urea on (110) ( ) and ( ) faces silver single crystals. It is found that in many of these cases there is pronounced effect on the deposit crystal habit and there is strong development of {Ill } faces on the (110) silver face . It appears that the brightening effect of these agents must be connected with their pronounced effect on the crystal habit leading to flat facets of relatively large extent and high smoothness compared with the wave length of light, rather than with any marked decrease of grain size . Optical micrographs are also shown to illustrate the deposit surface form .
Rfsumβ¬-Utilisation de la diffraction d'β¬lectrons en vue d'6tudier ]a modification de structure superficielle d'6lectro-dAp6ts d'Ag, 8 partir de bains Ag(CN)s en presence d'agents additionnels tels que sulfure de carbon, thio-semi-carbazide, thio-u , urβ¬e et sur les faces (110) (111) (100) de monocristaux Ag . Leur effet sur la forme du depot est prononca dens certains call, oil I'on observe on d6veloppement notable des faces (111) sur les faces (110) . Il apparait que de telles influences sur la forme sent en relation avec le brillant que confa rent ces agents, des facettes plates d'8tendue relativement grande presentant un haut degr6 de lissage comparativement aux longueurs d'ondes lumineuses, sans diminution sensible de 1a grosseur des grains. Des micrographies optiques en rendent compte d'autre part .