An apparatus according to one embodiment includes a module having a tape bearing surface and a plurality of tunnel valve read transducers arranged in an array extending along the tape bearing surface of the module. Each of the tunnel valve read transducers includes a sensor structure having a free layer, a tunnel barrier layer, and a reference layer. At least some of the sensor structures are recessed from a plane extending along the tape bearing surface. An at least partially polycrystalline coating is positioned on a media facing side of the recessed sensor structures.