An apparatus comprises a slider comprising an air bearing surface (ABS) and configured for heat-assisted magnetic recording. The slider includes a writer and a reader at the ABS, a near-field transducer (NFT) proximate the writer, and an optical waveguide optically coupled to a laser source and the NFT. The slider further includes a sensor configured to contact and sense thermal asperities of a magnetic recording medium. The sensor is formed from one of Ru, Rh, Pd, Os, Ir, and Pt.