Characterization of ggr;hyphen;Fe2O3homogeneity in magnetic recording media by photoacoustics

摘要

The degree of homogeneity of ferric oxide in magnetic tapes has been characterized using photoacoustic techniques. The method is based on excitation of the sample by a modulated laser beam and subsequent detection of its acoustic response via a condenser microphone. The acoustic response is dependent on the local thermal variations in the sample, and is a direct measurement of the distribution uniformity of the particulate metal oxide in the sample. Results of this study provide a potential means for the rapid evaluation of the quality of magnetic recording media.