A magnetic field generating device comprising a frame about which a current carrying coil of conductor is wound. This thin film single pole head for perpendicular magnetic recording is formed on a reproducing head composed of a pair of shield layers formed on a substrate, and a reproducing element formed therebetween. One or more parameters of the sample are measured by means of at least two spectroscopic techniques, wherein the at least two different spectroscopic techniques are selected from the group consisting of:.