 The alloy has a low coercivity, near zero magnetostriction, and significant anisotropic magnetoresistance.The low magnetostriction is critical for industrial applications, where variable stresses in thin films would otherwise cause a ruinously large variation in magnetic properties.Mu-metal was developed by British scientists Willoughby S. Smith and Henry J. Garnett and patented in 1923 for inductive loading of submarine telegraph cables by The Telegraph Construction and Maintenance Co. Ltd. (now Telcon Metals Ltd.), a British firm that built the Atlantic undersea telegraph cables.