Point-dipole response from a magnetic force microscopy tip with a synthetic antiferromagnetic coating

A point-dipole-like magnetic force microscopy tip has been realized using an antiferromagnetically coupled synthetic structure consisting of two CoCrPt layers separated by an ultrathin Ru layer. This is made possible through magnetizing one of the CoCrPt layers in either upward or downward direction along the tip axis and the other in the opposite direction through antiferromagnetic coupling. The new tip was found to have a superior resolution and a point-dipole-like magnetic response when being used to image magnetic patterns recorded on longitudinal media. (C) 2003 American Institute of Physics.