Comparative study of giant magnetoresistance in CoZr/Cu and Co/Cu multilayers

• Published in: Journal of magnetism and magnetic materials Vol. 165; no. 1; pp. 284 - 287
• Main Authors: Bouziane, K., Ben Youssef, J., El Harfaoui, M., Koshkina, O., Le Gall, H., Desvignes, J.M., El Yamani, M., Fert, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1997
• Subjects: Exchange coupling; Giant magnetoresistance; Interface roughness; interlayer; Multilayers; Ultrasoft magnetic properties; interlayer; Multilayers; Giant magnetoresistance; Exchange coupling; Ultrasoft magnetic properties; Interface roughness
• ISSN: 0304-8853
• DOI: 10.1016/S0304-8853(96)00530-6

Since amorphous Co 100− x Zr x alloys present ultrasoft properties, higher sensitivity is expected in CoZr/Cu multilayers compared to the Co/Cu system as investigated in the present work from two types (I and II) of hybrid magnetic structures [(F 1/F 2/F 1)Cu] 15 where (F 1/F 2/F 1) is a magnetic sandwich corresponding to either [(CoZr/Co/CoZr)] 15 (type I) or [(Co/CoZr/Co)Cu] 15 (type II) and F 1 is a very thin magnetic layer inserted at the interfaces between the Cu layer and the magnetic F 2-based multilayers. Strong changes in the magnetization hysteresis curve, the indirect exchange coupling J and the magnetoresistive properties are observed with the insertion of a very thin magnetic CoZr (Co) layer at the interfaces between Cu spacer layers and the magnetic Co (CoZr) layer in Co/Cu (CoZr/Cu) multilayers. Insertion of a 2 Å thick CoZr layer into interfaces of the Co/Cu type I multilayers induces significant reduction by a factor 5 of J and the magnetoresistance Δ R/R. Opposite evolution is observed when a thin Co layer is inserted in CoZr/Cu type II multilayers. The dependences of the magnetic and magnetoresistive characteristics with the insertion are correlated with the interface roughness change as deduced from XRD at low angles.