Topographic image (left) and Magnetic Force Microscopy (MFM) phase image (right) of a HDD platter surface. The high and low areas on the magnetic scan are regions with different orientation of the magnetic dipoles that store binary 1s and 0s.
スキャン BudgetSensors MagneticMulti75-G
AFM probe in Magnetic Force Microscopy mode, 5 micron scan size
Image courtesy of Dr. Yordan Stefanov, Innovative Solutions Bulgaria