Magnetic force microscope

A magnetic force microscope comprising:

• a magnetized cantilever having a supported end and a free end on opposite sides;
• a probe attached to said free end of said cantilever;
• a first oscillation means for exciting said cantilever into oscillation such that said cantilever oscillates at a given oscillation frequency of f0 and with a given amplitude when said cantilever is spaced from a sample by such a distance that no force is exerted between the cantilever and the sample;
• a second oscillation means for exciting said cantilever into oscillation such that the oscillation frequency of said cantilever is held at a given oscillation frequency f0′;
• a selector means for selecting one of excitation of said first oscillation means and excitation of said second oscillation means applied to the cantilever;
• a distance control means for controlling said selector means such that the cantilever is excited into oscillation by said first oscillation means and for controlling the distance between the cantilever and the sample to cause the oscillation frequency of said cantilever to shift from f0 to f1 wherein f1 is less than f0 (f1<f0) so that said probe taps the observation positions (xi, yj) on the sample;
• a topographic means for obtaining topographic information about the sample in the observation positions (xi, yj) on the sample based on results of control provided by said distance control means;
• a position-setting means for placing said probe in the observation positions (xi, yj) on the sample and for maintaining the distance between said cantilever and said sample at a distance used on collection of said topographic information;
• an amplitude control means for controlling said selector means to cause said second oscillation means to excite the cantilever into oscillation when the probe is placed in position on the sample by said position-setting means and for controlling said second oscillation means such that the amplitude of said cantilever under this condition does not permit said probe to tap the sample;
• and
• a means for obtaining magnetic information about the sample in the observation positions (xi, yj) on the sample based on the phase difference between a signal indicating oscillation of the cantilever and the oscillation signal from said second oscillation means when the probe has been placed in position on the sample by said position-setting means and the cantilever is oscillating while said amplitude control means prevents the probe from tapping the sample.