Permalloy Electrodeposited Films with the Addition of Sn

Magnetic nickel-iron alloy films with added Sn were plated in a citric bath (a bath containing sodium citrate and citric acid) employing a periodic current-pulse plating technique with synchronous agitation. Agitation was periodically applied during part of the cycle current-off time (approximately 15 sec) and stopped just before the cycle current-on time (1 sec). The precise Sn-, Fe-and Ni-content dependencies of Hc, ¿i, Bs and Hk of films were clarified for compositions centered on the bulk permalloy composition, and the hardness Hv and etch rate were compared with those of some electroplated alloy films (81 Ni-Fe, 45 Ni-Fe, permalloy with added Sn). The addition of Sn to Ni-Fe electroplated films not only resulted in excellent soft magnetic properties, but also acted to improve the film chemical and mechanical properties.