Defect dependent polarized spin current in 1% Co doped ZnO thin films

Abstract

The magnetic nature in Co and W doped ZnO lattice, which included specific concentration of defects, is investigated by magneto electrical measurements. The results are reported based upon the findings of longitudinal and transverse magneto electrical transport changes at 2 K. The transverse magneto electrical transport analyses are carried out with the scanning speeds of 20 Oe/s, 50 Oe/s, 100 Oe/s and 190 Oe/s in order to understand the relaxation of polarized spins. In the highest scan speed of 190 Oe/s, the relation between the polarized spins and positive magneto resistivity is revealed through both hole and electron mediated interactions. Although Hall resistance measurements show the dominant carriers as n-type, the 10 +/- 1% positive magneto resistivity and a split of about 3.1 +/- 0.2 Ohm in magneto hysteresis curve prove that a polarized spin current is formed under both s-d and p-d interactions effectively. (C) 2014 Elsevier B.V. All rights reserved.