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 H
_c
, μ
_i
, B
_s
and H
_k
of films were clarified for compositions centered on the bulk permalloy composition, and the hardness H
_v
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.