header, Scanning magneto-resistive microscope (SMRM)

This facility is conceptually very simple, but its implementation represents current state-of-the-art precision in closed loop miniaturized, feed back scanning technology. In brief, a desired transducer (typically a magnetoresistive read/write head assembly including slider and suspension) is mounted above a coupon or hard disk platter (up to 3 1/2 inch) which in turn may be raster scanned over a 100 micron by 100 micron field with a step precision of 1 nanometer. The scanning stage actually has five degrees of freedom, including xyz with the resolution of 1 nanometer and 2 angles of rotation with resolution of 10 nanoradians.

Because the output of a magnetoresistive head is independent of velocity, appreciable signals can be developed while scanning in contact with typical modern disk or tape media. The advantages of the SMRM include the ability to work with true "contact recording," nanometer precision, without fluctuations in flying height or track radial runout. Examples of the nature and the quality of the data that are obtained may be found in the following publications:

Yamamoto, S. Y., and Schultz, S., "Scanning magneto-resistance microscopy", published in Applied Physics Letters, 69, #21, 3263-5 (1996).

Yamamoto, S. Y. and Schultz, S.: "Scanning magneto-resistance microscopy (SMRM): imaging with a MR head", published in Conf. Proc. of MMM'96 Atlanta 11/12-15/96 , J. Appl. Phys., 81 (#8), 4696 (1997).

Yamamoto, S. Y., Schultz, S., Zhang, Yun, and Bertram. H. Neal, "Scanning magnetoresistance microscopy (SMRM) as a diagnostic for high density recording", published in Proc. of TMRC'96 in IEEE Trans Mag. (1996).