Electrochemical deposition of amorphous FeB films with soft magnetic properties

To obtain FeB amorphous plated films with soft magnetization and high magne tostriction, effects of three kinds of agents [sodium L-ascorbate (C6H7NaO6 ), thiourea (NH2CSNH2), and ammonium sulfate ((NH4)(2)SO4)] on magnetic and magnetoelastic properties of films were investigated systematically. The f irst two agents, C6H7NaO6 and NH2CSNH2 were found to be ineffective for imp roving the soft magnetic properties of films. To the contrary, however, (NH 4)(2)SO4 is very effective for the magnetic softening: Amorphous FeB plated films with coercivity less than 4 Oe were obtained by employing the bath c omposition of FeSO4 . 7H(2)O (71.9 mM), KBH4 (296.6 mM), NaOH (400 mM), KNa C4H4O6 . 4H(2)O (600 mM) and (NH4)(2)SO4 (80 mM). These soft films exhibite d a favorable large magnetostriction of 26 x 10(-6), being adequate for mic romagnetoelastic devices. (C) 1998 American Institute of Physics. [S0021-89 79(98)41111-3].