Devices having an air bearing surface (ABS), the devices including a write pole; a near field transducer (NFT) that includes a peg and a disc, wherein the peg is at the ABS of the device; a heat sink positioned adjacent the disc of the NFT; a dielectric gap positioned adjacent the peg of the NFT at the ABS of the device; and a conformal diffusion barrier layer positioned between the write pole and the dielectric gap, the disc, and the heat sink, wherein the conformal diffusion barrier layer forms at least one angle that is not greater than 135°.