Optimizing the NIST magnetic imaging reference sample

We have further developed the NIST magnetic imaging reference sample to include a magnetic pattern which can indicate the magnetic polarity of a magnetic force microscope tip. Several samples cut from the same disk were measured with a single tip. We have also measured a single transition with several tips. Both measurements have shown the variability in images taken with different tips and different instrument configuration which underscores the need for a well calibrated sample.