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Title: Alternative material study for heat assisted magnetic recording transducer application

In heat assisted magnetic recording (HAMR), optical near field transducer (NFT) is a key component. Au is currently used as NFT material because of its strong surface plasmon effect. Due to the soft property of Au material, reliability of Au NFT becomes a key issue for realizing HAMR production. In this paper, the possibility of alternative materials, including transition metal nitrides (TMNs) and transparent conducting oxides (TCOs) to replace Au is studied. The results show that all of the listed TMN and TCO materials can meet the mechanical requirements at room temperature in terms of hardness and thermal expansion. An optical model, which includes optical waveguide, NFT and FePt media, is used to simulate NFT performances. The results indicate that the resonant wavelengths for NFT with TCO materials are longer than 1500 nm, which is not suitable for HAMR application. TMN materials are suitable for NFT application at wavelength band of around 800 nm. But the NFT efficiency is very low. ZrN is the best material among TMN materials and the efficiency of ZrN NFT is only 13% of the Au NFT's efficiency. Reducing refractive index (n) and increasing extinction coefficient (k) will both lead to efficiency increase. Increasing k contributes moremore » in the efficiency increase, while reducing n has a relatively low NFT absorption. For materials with the same figure of merit, the NFT with larger k material has higher efficiency. Doping materials to increase the material conduction electron density and growing film with larger size grain may be the way to increase k and reduce n.« less
Authors:
; ; ;  [1]
  1. Data Storage Institute, Agency for Science, Technology and Research A*STAR, 5, Engineering Drive 1, Singapore 117608 (Singapore)
Publication Date:
OSTI Identifier:
22410002
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; EFFICIENCY; ELECTRON DENSITY; FILMS; GOLD; HARDNESS; HEAT; INTERMETALLIC COMPOUNDS; IRON; OPTICAL MODELS; OXIDES; PLASMONS; PLATINUM; REFRACTIVE INDEX; SURFACES; TEMPERATURE RANGE 0273-0400 K; THERMAL EXPANSION; TRANSDUCERS; ZIRCONIUM NITRIDES