  Ferromagnetic (FM) layers separated by nonmagnetic metallic spacer layers can
exhibit Ruderman Kittel Kasuya Yosida (RKKY) coupling which may lead to a
stable synthetic antiferromagnetic (SAF) phase. In this article we study
magnetization reversal in [Co/Pt] layers by varying the number of bilayer
stacks (Pt/Co) as well as thickness of Ir space layer tIr on rigid Si(100) and
flexible polyimide substrates. The samples with tIr = 1.0 nm shows a FM
coupling whereas samples with tIr = 1.5 nm shows an AFM coupling between the FM
layers. At tIr = 2.0 nm, it shows a bow-tie shaped hysteresis loop indicating a
canting of magnetization at the reversal. Higher anisotropy energy as compared
to the interlayer exchange coupling (IEC) energy is an indication of the
smaller relative angle between the magnetization of lower and upper FM layers.
We have also demonstrated the strain induced modification of IEC as well as
magnetization reversal phenomena. The IEC shows a slight decrease upon
application of compressive strain and increase upon application of tensile
strain which indicates the potential of SAFs in flexible spintronics.
