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 each embodiment the sensor includes an in-situ naturally oxidized specularly reflecting layer (NOL) which is a more uniform and dense layer than such layers formed by high temperature annealing or reactive-ion etching. In one embodiment, the sensor has an ultra thin composite free layer and a high-conductance layer (HCL), providing high output and low coercivity. In a second embodiment, along with the same NOL, the sensor has a laminated free layer which includes a non-magnetic conductive layer, which also provides high output and low coercivity. The sensors are capable of reading densities exceeding 60 Gb/in.sup.2.