Excess low frequency conduction noise in a granular composite

• Published in: Solid state communications 1981, Vol.37 (4), p.353-357
• Main Authors: Mantese, J.V., Goldburg, W.I., Darling, D.H., Craighead, H.G., Gibson, U.J., Buhrman, R.A., Webb, W.W.
• Format: Article
• Language: English
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/0038-1098(81)90375-6

Granular composites consisting of 25% nickel as 8 nm diameter particles dispersed in an aluminium oxide matrix display excess conduction noise. Co-deposited films with resistance per square about 10 5 ohms and negative temperature coefficient show a noise power spectral density S v(ƒ) = S v(1) ƒ α where α ≅ 1.10 ± 0.03 over the accessible spectral range of 0.1 Hz ≲ ƒ ≲ 5000 Hz. The amplitude 3 × 10 −15 ≲ S v (1) ≲ 5 × 10 −12 V 2Hz −1, appears to increase approximately quadratically as the applied voltage V s up to V s ≲ 2.5 V and as the first power of V s for 2.5 ≲ V s < 35 V.