Heat-assisted magnetic recording head having near-field transducer with nanorod and diffusion barrier plate

A method comprising:

• coupling light from a waveguide to a near-field transducer near a media-facing surface of a recording head, the near-field transducer having a plasmonic diffusion barrier plate that is stacked on a surface plasmonic plate on a plane normal to the media-facing surface, a bottom surface of the plasmonic diffusion barrier plate facing the waveguide and formed of a material that is more mechanically robust than that of the surface plasmonic plate;
• in response to the coupling of the light to the near-field transducer, propagating surface plasmons at the bottom surface of the plasmonic diffusion barrier plate, causing the surface plasmons to be concentrated at a narrowed end of the plasmonic diffusion barrier plate that faces the media-facing surface;
• and
• exciting a nanorod with the concentrated surface plasmons, the nanorod stacked on the bottom surface of the plasmonic diffusion barrier plate and extending towards the media-facing surface, the excited nanorod directing the concentrated surface plasmons out of the media-facing surface to heat a recording medium.

A recording head comprising:

• a write pole tip that extends to a media-facing surface;
• a heat sink that is thermally coupled to a side of the write pole tip between the write pole tip and waveguide core;
• and
• a near-field transducer comprising a nanorod extending towards the media-facing surface and stacked on a surface plasmonic plate of the near-field transducer, the surface plasmonic plate in contact with the heat sink, the nanorod comprising a body and a protrusion extending from an edge of the body that faces away from the media-facing surface, the protrusion having a downtrack thickness that is less than that of the body, the protrusion being absorbed into the body in response to a high temperature and reducing a recess of the body from the media-facing surface in response to the high temperature.