Effect of MgO spacer and annealing on interface and magnetic properties of ion beam sputtered NiFe/Mg/MgO/CoFe layer structures

Journal Article · Sat Sep 15 04:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4752264· OSTI ID:22089456

Bhusan Singh, Braj; Chaudhary, Sujeet ^[1]

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1. Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016 (India)

The effect of variation in the thickness of ion assisted ion beam sputtered MgO spacer layer deposited at oxygen ion assisted energy of 50 eV on the extent of magnetic coupling of NiFe and CoFe layers in Si/NiFe(10 nm)/Mg(1 nm)/MgO(2,4,6 nm)/CoFe(10 nm) sandwich structure is investigated. At MgO spacer layer thickness of 4 nm, the separate reversal of magnetizations of the two ferromagnetic layers is observed in the hystresis loop recorded along easy direction. This results in a 3.5 Oe wide plateau like region during magnetization reversal, which became 4.5 Oe at 6 nm thin MgO. At 2 nm thin MgO, the absence of plateau during magnetization reversal region revealed ferromagnetic coupling between the two ferromagnetic layers, which is understood to arise due to the growth of very thin and low density (1.22 gm/cc) MgO spacer layer, indicating the presence of pinholes as revealed by x-ray reflectometry. After vaccum annealing (200 Degree-Sign C/1 h), the plateau region for 4 and 6 nm thin MgO case decreased to 1.5 Oe and 2.0 Oe, respectively, due to enhanced interface roughness/mixing. In addition, an enhancement of the in-plane magnetic anisotropy is also observed.

• OSTI ID: 22089456
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 112; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
ANNEALING
COBALT ALLOYS
DEPOSITION
FERROMAGNETIC MATERIALS
INTERFACES
ION BEAMS
IRON ALLOYS
MAGNESIUM
MAGNESIUM OXIDES
MAGNETIC PROPERTIES
MAGNETISM
MAGNETIZATION
NICKEL ALLOYS
ROUGHNESS
SPACERS
THICKNESS
THIN FILMS
X RADIATION