A new swept-frequency permeameter for measuring the complex permeability of thin magnetic films

A permeameter is described that measures the complex permeability of anisotropic thin magnetic films over a continuous frequency spectrum. The system resolves the permeability into both real and imaginary parts, or magnitude and phase. The frequency span of the permeameters, 0.1-200 MHz, is larger than that of previously reported permeameters. The system has a measurement error of approximately 1%, which for the samples used here corresponds to a low-level permeance detection limit of about 1 μm, an order of magnitude below the previously reported low level limit of 13 μm. The system is both compact in size and convenient to use, with measurements taken over the whole frequency range in less than a minute