Title :
Thermal stability of NiMn spin valve heads
Author :
Zhang, Y.B. ; van der Heijden, P.A.A. ; Nozieres, Jean-Pierre ; Pentek, K. ; Chin, T.K. ; Tuchscherer, T. ; Zeltser, A.M. ; Blank, H.-R. ; Trotter, S. ; Jaren, S. ; Speriosu, V.S.
Author_Institution :
Appl. Magnetics Corp., Goleta, CA, USA
fDate :
5/1/2000 12:00:00 AM
Abstract :
The thermal stability of NiMn-based spin valves was studied both at the coupon level and in full read/write heads. In the coupons, the blocking temperature distribution showed no component below 150°C. As a result, the exchange field at elevated temperature was found to increase with time (because of improved chemical ordering of the NiMn layer), and irreversible losses in the ΔR/R response were observed only above 250°C (because of layer interdiffusion). If a 10% drop in ΔR/R amplitude is used as a criterion to calculate time to failure, the NiMn heads should have several hundred years of lifetime at 150°C operating temperature. Full read/write heads showed linear response with read-back amplitudes above 2 mV/μm at 6-mA operating current. In contrast to most other giant magnetoresistance heads, the output of the head remains the same after heating with a high bias current and degrades only with the shorting of the stripe. All these properties make NiMn superior to other antiferromagnets for spin valve head applications
Keywords :
antiferromagnetic materials; magnetic heads; manganese alloys; nickel alloys; spin valves; thermal stability; 150 to 250 C; 6 mA; NiMn; NiMn spin valve head; antiferromagnet; blocking temperature distribution; chemical ordering; coupon; exchange field; giant magnetoresistance; irreversible loss; layer interdiffusion; read/write head; thermal stability; time-to-failure; Antiferromagnetic materials; Chemicals; Giant magnetoresistance; Heating; Legged locomotion; Magnetic heads; Spin valves; Temperature distribution; Thermal degradation; Thermal stability;
Journal_Title :
Magnetics, IEEE Transactions on