Title :
Giant interface magnetostriction and temperature dependence in NiFe films encapsulated with Ta and Al2O3 layers
Author_Institution :
Quantum Corp., Shrewsbury, MA, USA
fDate :
9/1/1999 12:00:00 AM
Abstract :
The interface magnetostriction (MS), λi of NiFe films (thicknesses:50 to 500 Å) encapsulated with Ta and Al2 O3 layers was studied in as-deposited and thermally annealed states. The MS of NiFe films encapsulated with only Ta (or Al 2O3) layers increase (or decrease) rapidly with decreasing NiFe thickness, due to giant positive (or negative) λ i. The magnitudes of both positive and negative λi increase noticeably with processing at elevated temperatures. In structures containing Ta/NiFe and NiFe/Al2O 3 interfaces, the total interfacial MS contribution is greatly reduced due to the opposite signs of λi at NiFe interfaces, leading to negligible thickness dependence of the effective MS in as-deposited and annealed states. The strong interfacial MS induced anisotropy affects markedly the uniaxial anisotropy of NiFe films for thicknesses below 100 Å
Keywords :
alumina; ferromagnetic materials; interface magnetism; iron alloys; magnetic anisotropy; magnetic thin films; magnetostriction; nickel alloys; tantalum; 50 to 500 A; Al2O3 layers; NiFe films; NiFe-Al2O3; NiFe-Ta; NiFe/Al2O3; Ta layers; Ta/NiFe; giant interface magnetostriction; interface magnetostriction; temperature dependence; thermally annealed states; thickness dependence; uniaxial anisotropy; Aluminum oxide; Animals; Annealing; Chemical engineering; Chemical hazards; Giant magnetoresistance; Magnetic field measurement; Magnetic films; Magnetic heads; Magnetostriction; Mobile robots; Optical films; Particle swarm optimization; Rapid thermal processing; Robot kinematics; Robot sensing systems; Robustness; Temperature dependence;
Journal_Title :
Magnetics, IEEE Transactions on
