%0 Journal Article
%K Lead
%K Nanostructured materials
%K Zirconium
%K Ferroelectric materials
%K Nanotechnology
%K Ferroelectricity
%K Proof of concept
%K Strontium titanates
%K Negative capacitance
%K Strontium alloys
%K Heterojunctions
%K Capacitance
%K Experimental evidence
%K Nanocomposite films
%K Nanoscale
%K Mean field theory
%K Bi-layer
%K Capacitance enhancement
%K Classical limits
%K Gate oxide
%K NanoScale Transistors
%K Negative capacitance effect
%K SrTiO
%K Subthreshold slope
%K Tuning parameter
%A A. Islam Khan
%A D Bhowmik
%A P Yu
%A S. Joo Kim
%A X Pan
%A Ramamoorthy Ramesh
%A S Salahuddin
%B Applied Physics Letters
%D 2011
%G eng
%R 10.1063/1.3634072
%T Experimental evidence of ferroelectric negative capacitance in nanoscale heterostructures
%V 99
%X We report a proof-of-concept demonstration of negative capacitance effect in a nanoscale ferroelectric-dielectric heterostructure. In a bilayer of ferroelectric Pb(Zr0.2Ti0.8)O3 and dielectric SrTiO3, the composite capacitance was observed to be larger than the constituent SrTiO3 capacitance, indicating an effective negative capacitance of the constituent Pb(Zr0.2Ti0.8)O3 layer. Temperature is shown to be an effective tuning parameter for the ferroelectric negative capacitance and the degree of capacitance enhancement in the heterostructure. Landau's mean field theory based calculations show qualitative agreement with observed effects. This work underpins the possibility that by replacing gate oxides by ferroelectrics in nanoscale transistors, the sub threshold slope can be lowered below the classical limit (60 mV/decade). © 2011 American Institute of Physics.