Journal of Physics D: Applied Physics PAPER Voltage-controlled negative differential resistance in metal-sputtered alumina-Si structures To cite this article: E Hourdakis et al 2019 J. Phys. D: Appl. Phys. 52 085101 View the article online for updates and enhancements. This content was downloaded from IP address 143.233.248.60 on 25/01/2019 at 10:18