Plasmon generator includes three metal layers for thermally-assisted magnetic recording

A thermally-assisted magnetic recording head comprising:

• a medium facing surface facing a recording medium;
• a main pole that produces a write magnetic field for writing data on the recording medium;
• a waveguide including a core through which light propagates, and a cladding provided around the core;
• and
• a plasmon generator having a front end face located in the medium facing surface, the plasmon generator including:
• a first layer formed of a first metal material;
• a second layer formed of a second metal material;
• and
• a third layer formed of a third metal material, wherein
• the first to third layers are stacked to be aligned in this order in a first direction,
• each of the first to third layers has a thickness in the first direction,
• the thickness of the second layer is smaller than the thickness of each of the first and third layers,
• each of the second and third layers has an end portion, the end portion lying at an end in a second direction orthogonal to the first direction and constituting part of the front end face,
• the first layer does not have any portion constituting part of the front end face,
• the first and second metal materials are higher in electrical conductivity than the third metal material,
• the third metal material is higher in Vickers hardness than the first and second metal materials,
• the first layer has a plasmon exciting part configured to excite a surface plasmon thereon through coupling with evanescent light generated from the core, and
• the front end face generates near-field light based on the surface plasmon.