Title :
FePt/Fe Exchange Coupled Composite Structure on MgO Substrates
Author :
Ma, Bin ; Wang, Hao ; Zhao, Haibao ; Sun, Chengjun ; Acharya, Ramamurthy ; Wang, Jian-Ping
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Minnesota, Minneapolis, MN, USA
fDate :
6/1/2010 12:00:00 AM
Abstract :
A core-shell type exchange-coupled composite (ECC) structure is developed with an L10 phase FePt core and an Fe shell. Coercivity decreases from 30.6 kOe for the FePt granular film with a very thin thickness of 3.2 nm, to 7.85 kOe for the FePt/Fe core-shell type granular film with a 3-nm-thick Fe. The energy barriers of the FePt/Fe films are measured by using Sharrock equation. A modified formula of gain factor considering the effect of films´ thickness is proposed. Core-shell type FePt/Fe ECC granular film has a large advantage over a conventional granular film for media application.
Keywords :
coercive force; discontinuous metallic thin films; exchange interactions (electron); ferromagnetic materials; iron; iron alloys; magnetic hysteresis; magnetic multilayers; magnetic thin films; nanocomposites; nanomagnetics; platinum alloys; FePt-Fe; L10 phase core; MgO; Sharrock equation; coercivity; core-shell type exchange-coupled composite structure; core-shell type nanocomposite structure; energy barriers; gain factor; granular film; hysteresis loop; magnetization; size 3.2 nm; Coercive force; Energy barrier; Iron; Magnetic cores; Magnetic films; Magnetic materials; Magnetic recording; Optical films; Substrates; Writing; $L1_{0}$ FePt; Core-shell structure; ECC media; gain factor;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2009.2039858