Study of magnetic tunnel junction read sensors

Unshielded magnetic tunnel junction (MTJ) sensors stabilized by insulating hard magnetic tails have been fabricated. Testing results showed that the c ontrol of oxidation condition was important for obtaining MTJ with low junc tion resistances and high TMR coefficients. The results also showed that th e thickness of insulating spacer between hard magnet and MTJ stack had a si gnificant influence on sensor stability. Finally, recording tests of stabil ized MTJ read heads demonstrated linear densities of 420 Kbpi at 10(-9) ont rack error.