Electrodeposition of Sm-Co Permanent Magnets From Aqueous Media

Abstract

Aqueous electrodeposition of Sm-Co thin film magnetic alloys has been investigated with Hull cell and parallel electrodes using DC and pulse current (PC) methods. The basic solution consisted of 1M Sm sulfamate, 0.05M Co sulfate and 0.15M glycine. Most experiments were conducted at either 25oC or 60oC and various current densities (CD). Sufficient Sm deposit content was achieved to produce the SmCo5 (16.7 at % Sm) and Sm2Co17 (10.5 at % Sm) intermetallics by heat treatment. Parallel experiments confirmed the Hull cell results that increased temperatures and CDs increased Sm content of Sm-Co alloy deposits. Magnetic saturation decreased linearly and coercivity decreased nonlinearly with increased Sm content. Crystalline structures changed to non-crystalline with increase in Sm content. Increased Sm content tended to change magnetic properties from anisotropic to isotropic. For PC on parallel electrodes, higher PCD and lower bath temperatures increased Sm deposit content but decreased current efficiency.

DC Aqueous Electrodeposition of Sm-Co Permanent Magnets

“…Recently, Hull cell experiments on the aqueous electrodeposition of SmCo alloys provided an estimate of the operating conditions and solution compositions to obtain metallic high Sm content deposits (5). This paper reports on DC experiments with parallel electrodes and the resulting deposit magnetic properties.…”

Pulsed Aqueous Electrodeposition of Sm-Co Permanent Magnets

“…In our most recent report on investigations of the aqueous electrodeposition of rare earth (RE)-iron group (IG) alloys, we described results of work on DC electrodeposition of Sm-Co alloys. 1 These alloys are noted for their permanent magnet properties, but previously have not been successfully electrodeposited from aqueous media. The development of such a process will result in substantial reduction in manufacturing costs.…”