This paper deals with the planar Hall effect (PHE) of Ta(5)/NiFe(t F)/Cu(1.2)/NiFe(tp
)/IrMn(15)/Ta(5) (nm) spin-valve structures. Experimental investigations are performed for 50 ?m??50?m
junctions with various thicknesses of free layer (tF = 4, 8, 10, 12, 16, 26 nm) and pinned layer (tp = 1, 2, 6,
8, 9, 12 nm). The results show that the thicker free layers, the higher PHE signal is observed. In addition, the
thicker pinned layers lower PHE signal. The highest PHE sensitivity S of 196 ?V/(kA/m) is obtained in the
spin-valve configuration with tF = 26 nm and tp = 1 nm. The results are discussed in terms of the spin twist
as well as to the coherent rotation of the magnetization in the individual ferromagnetic layers. This
optimization is rather promising for the spintronic biochip developments. ?? 2009 IEEE.
Author Keywords: Biosensors; Hall effect; Magnetization reversal; Magnetoresistance; Magnetoresistive
devices
