Two embodiments of a GMR sensor of the bottom spin valve (BSV) spin filter spin valve (SFSV) type are provided, together with methods for their fabrication. In one embodiment, the sensor has an ultra thin (<20 angstroms) single free layer and a composite high-conductance layer (HCL), providing high output, low coercivity and positive magnetostriction. In a second embodiment, the sensor has a composite free layer and a single HCL, also having high output, low coercivity and positive magnetostriction. The sensors are capable of reading densities exceeding 60 Gb/in.sup.2.