Magnetic and Structural Properties of FePt-FeRh Exchange Spring Films for Thermally Assisted Magnetic Recording Media

Journal Article · Thu Jan 01 04:00:00 EST 2004 · IEEE Transactions on Magnetics

DOI:https://doi.org/10.1109/TMAG.2004.829325· OSTI ID:978065

Thiele, J. -U. ^[1]; Maat, S. ^[1]; Robertson, Lee ^[2]; Fullerton, E. E. ^[1]

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1. San Jose Research Center
2. ORNL

Recently a novel media structure for thermally assisted magnetic recording was proposed consisting of a layer of FePt exchange coupled to a FeRh layer. The FePt forms a high magnetocrystalline anisotropy, high coercivity ferromagnetic layer. The FeRh layer is antiferromagnetic at room temperature, but upon heating above a transition temperature becomes ferromagnetic with a large magnetic moment and low magnetocrystalline anisotropy. The coupled ferromagnetic FePt and FeRh layers form an exchange-spring system significantly lowering the coercive field of the composite system compared to a single layer of FePt. This feature opens intriguing possibilities for media applications for thermally assisted magnetic recording where the ferromagnetic phase of FeRh is exploited to help write the media while the low-temperature antiferromagnetic phase supports the long-term stability. Here temperature-dependent structural and magnetic measurements of undoped and doped FeRh single layer and FePt-FeRh bilayer films are presented and the promises and challenges of the exchange spring media structure are discussed.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Flux Isotope Reactor
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 978065
• Journal Information: IEEE Transactions on Magnetics, Journal Name: IEEE Transactions on Magnetics Journal Issue: 4 Vol. 40; ISSN IEMGAQ; ISSN 0018-9464
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
FILMS
HEATING
IRON ALLOYS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETIC TAPES
MORPHOLOGY
PHASE TRANSFORMATIONS
PLATINUM ALLOYS
RHODIUM ALLOYS
TEMPERATURE DEPENDENCE