Ledge-type Co/L1{sub 0}-FePt exchange-coupled composites

Journal Article · Tue Jun 21 04:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4953766· OSTI ID:22596809

Speliotis, Th.; Giannopoulos, G.; Niarchos, D. ^[1]; Li, W. F.; Hadjipanayis, G. ^[2]; Barucca, G. ^[3]; Agostinelli, E.; Laureti, S.; Peddis, D.; Testa, A. M.

---

1. Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Athens 15310 (Greece)
2. Department of Physics, University of Delaware, Newark, Delaware 19716 (United States)
3. SIMAU, Università Politecnica delle Marche, via Brecce Bianche, Ancona (Italy)

FePt-based exchange-coupled composites consisting of a magnetically hard L1{sub 0}-FePt phase exchange-coupled with a soft ferromagnetic material are promising candidates for future ultra-high density (>1 Tbit/in{sup 2}) perpendicular magnetic recording media, also being of interest for other applications including spin torque oscillators and micro-electro-mechanical systems, among others. In this paper, the effect of the thickness of a soft Co layer (3 < th{sub Co} < 20 nm) on the magnetic behavior of ledge-type fcc(100)-Co/L1{sub 0}(001)-FePt composites deposited on an MgO (100) substrate is systematically studied by combining morpho-structural analyses and angular magnetization measurements. Starting from a film consisting of isolated L1{sub 0}(001)–FePt islands, the ledge-type structure was obtained by depositing a Co layer that either covered the FePt islands or filled-up the inter-island region, gradually forming a continuous layer with increasing Co thickness. A perpendicular anisotropy was maintained up to th{sub Co} ∼ 9.5 nm and a significant reduction in the coercivity (about 50% for th{sub Co} ∼ 3 nm) with the increase in th{sub Co} was observed, indicating that, by coupling hard FePt and soft Co phases in a ledge-type configuration, the writability can be greatly improved. Recoil loops' measurements confirmed the exchange-coupled behavior, reinforcing a potential interest in these systems for future magnetic recording media.

• OSTI ID: 22596809
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 23 Vol. 119; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
COERCIVE FORCE
DENSITY
DEPOSITS
FCC LATTICES
FERROMAGNETIC MATERIALS
FILMS
IRON COMPOUNDS
LAYERS
MAGNESIUM OXIDES
MAGNETIZATION
OSCILLATORS
PLATINUM COMPOUNDS
RECOILS
SPIN
SUBSTRATES
THICKNESS
TORQUE