Patent ID: 7675717

Claim:
A magnetic head comprising: a read sensor having: a lower seed layer wherein said lower seed layer is chosen from a group consisting of Ta, NiFeCr, NiFeCoCr, NiFe, Cu, Ta/NiFeCr, Ta/NiFeCr/NiFe, Ta/Ru and Ta/NiFeCoCr; an upper seed layer wherein said upper seed layer is chosen from a group consisting of Ru, Cu, NiFe, Cu(x)Au(1−x)(x=0.22-0.5) alloys, Ru(x)Cr(1−x)(x=0.1-0.5) alloys, NiFeCr and NiFeCoCr; an AFM layer formed on said upper seed layer; and a ferromagnetic pinned layer formed on said AFM layer to form a partial sensor stack, wherein said partial sensor stack said post-annealing is done at a temperature in the range of 200 degrees C. to 250 degrees C. for a time span greater than 24 hours to produce a pinned layer which is pinned by exchange coupling with said AFM layer, where said exchange coupling energy has a Jk value of at least 1.3 erg/cm2.