Retention of Giant Magnetoresistance in Thin Films on Very Rough Substrates

Interfacial roughness is known to affect GMR. Past studies have measured increases , decreases or negligible changes in GMR produced by increasing interfacial roughness. Most studies have explored small scale interfacial roughness induced by changes in growth parameters or annealing$^{1}$. We present a study of the effects of large scale roughness ($\sigma _{rms}$ $>$ 5 nm) on the properties of GMR multilayers. GMR thin films were deposited on glass substrates chemically etched for different lengths of time producing a range of lateral and vertical roughness. We found that this long length scale does not have a significant detrimental effect suggesting that viable GMR multilayers can be deposited on a wide variety of surfaces, even with large roughness. M. C. Cyrille et al. Phys. Rev. B, 62, 3361 (2000), J. M. Colino et al., Phys. Rev. B, 54, 13030 (1996). $^{2}$ W. F. Egelhoff, Jr. et al., J. Appl. Phys., 82, 6142 (1997) $^{3}$ J. Alicea and S. Hershfield, J. Appl. Phys., 93, 7930 (2003)