Intergranular Exchange Coupling in FePt:X:FePt ( =, C, , Cr and ) Thin Films for Heat Assisted Magnetic Recording

• Published in: IEEE transactions on magnetics Vol. 48; no. 11; pp. 2746 - 2748
• Main Authors: Granz, Steven D., Kryder, Mark H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.11.2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Couplings; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; FePt; HAMR; intergranular exchange coupling; L10 media; Magnetic hysteresis; Magnetic recording; Magnetism; Materials science; Media; Methods of deposition of films and coatings; film growth and epitaxy; Other topics in materials science; Perpendicular magnetic anisotropy; perpendicular media; Physics; Saturation magnetization; Thin films; FePt; Platinum; perpendicular media; Iron; intergranular exchange coupling; Magnetic recording; Magnetic properties; HAMR; L10 media
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2012.2194698

In this study we quantitatively determined the exchange coupling across B, C, SiO x , Cr and TaO x segregants by measuring the exchange coupling between two FePt layers separated by segregant layers of varying thickness. Our study indicates that the segregant that provides the best exchange break is TaO x ; whereas, C is the worst and SiO x , Cr and B are in between. Our data indicates that a segregant intergranular region thicker than 0.8 nm should decouple FePt grains if B, TaO x , SiO x , or Cr are used, but with C, a thickness greater than 1 nm is required.