Structure and properties of electrodeposited silver–bismuth alloys

Internal stress in multilayer silver–bismuth coatings

“…In similar cases the coatings are composed of darker and lighter lamellas containing larger or smaller amounts of the alloying element. The Ag-Bi alloy coatings are heterogeneous, two-phase and are composed of regions containing almost pure silver or pure bismuth [12]. The spatial separation of the two phases leads to the formation of a columnar structure, onto which in some cases a superpositioned lamellar structure is observed.…”

“…The spatial separation of the two phases leads to the formation of a columnar structure, onto which in some cases a superpositioned lamellar structure is observed. Some of the properties of the alloy coatings electrodeposited under various conditions are described in a previous paper [12]. For example, when the percentage of bismuth in the coating increases, negative internal stress is produced as a result of both the stretching of the silver lattice at low bismuth concentration and the formation of a solid phase solution, as well as the stress of the pure bismuth phase of the heterogeneous alloy coatings [12].…”

“…Some of the properties of the alloy coatings electrodeposited under various conditions are described in a previous paper [12]. For example, when the percentage of bismuth in the coating increases, negative internal stress is produced as a result of both the stretching of the silver lattice at low bismuth concentration and the formation of a solid phase solution, as well as the stress of the pure bismuth phase of the heterogeneous alloy coatings [12]. The formulation of the electrolyte is optimised in such a way that offers a possibility to electrodeposit Ag-Bi alloy coatings with random percentage composition; i.e.…”

New examples of electrodeposited alloy systems with pattern formation

“…They reported about the observation of "crystallization spirals" formed by indium-richer phases on the surface of the alloy coating. Later similar structures were observed during electrodeposition of many other alloy systems, at the beginning starting with some other silver alloys, like AgSb [2,3], AgBi [4], AgIn [5], AgCd [6], AgSn [7], deposited from alkaline cyanide electrolytes. Later the phenomenon was discovered in some other alloy systems electrodeposited from acid, non-cyanide electrolytes (InCo [8], CuSb [9], SbCo [10]).…”

“…Different forms of spatio-temporal organized structures are observed -spots, waves, targets and spirals. They differ in their size, periods (more than 10 times larger period in AgIn [20,21], than in the AgSb [2,22] [4] structures) and phase composition. The main difference between the different phases in each system allowing their recognition and observation is the difference in their optical properties (dark and light areas).…”