Title :
In situ and ex situ observation of spin valves obtained by ion-beam deposition
Author :
Guarisco, D. ; Kay, E. ; Wang, Shan X.
Author_Institution :
Dept. of Mater. Sci. & Eng., Stanford Univ., CA, USA
fDate :
9/1/1997 12:00:00 AM
Abstract :
“Bottom” spin valves of the type NiO/15 Å NiFe/15 Å Co/tCu Cu/20 Å Co/50 Å NiFe were prepared by ion-beam deposition (IBD) on a Si(100)/NiO substrate. It is found that cleaning the substrates by ion-beam etching prior to the deposition of the multilayer has a significant influence on the magnetic properties of the spin valve. In particular, longer etching leads to a decrease in the exchange field and an increase in the coercivity of the pinned layer, without affecting the GMR ratio. A maximum GMR of 11.2% at room temperature is obtained for tCu=20 Å and 240 s etching time. The NiO substrate before and after ion-beam etching has been studied by atomic force microscopy (AFM). No significant change in roughness is observed, but the etched substrate shows smaller features
Keywords :
antiferromagnetic materials; atomic force microscopy; cobalt; coercive force; copper; exchange interactions (electron); ferromagnetic materials; giant magnetoresistance; interface structure; iron alloys; magnetic multilayers; nickel alloys; nickel compounds; soft magnetic materials; sputter deposition; sputter etching; surface cleaning; surface topography; 15 A; 20 A; 20 C; 240 s; 50 A; AFM; GMR ratio; NiO substrate; NiO-NiFe-Co-Cu-Co-NiFe; NiO/NiFe/Co/Cu/Co/NiFe; Si(100)/NiO substrate; atomic force microscopy; bottom spin valves; cleaning; coercivity; etched substrate; etching time; ex situ observation; exchange field; in situ observation; ion-beam deposition; ion-beam etching; magnetic properties; pinned layer; room temperature; roughness; spin valves; Cleaning; Magnetic properties; Materials science and technology; Monitoring; Nonhomogeneous media; Spin valves; Sputter etching; Sputtering; Temperature; Voltage;
Journal_Title :
Magnetics, IEEE Transactions on
