Multiple polarization states in symmetric ferroelectric heterostructures for multi-bit non-volatile memories. Issue 48 (30th November 2017)

• Record Type: Journal Article
• Authors: Boni, Georgia A.; Filip, Lucian D.; Chirila, Cristina; Pasuk, Iuliana; Negrea, Raluca; Pintilie, Ioana; Pintilie, Lucian
• Is Part Of: Nanoscale. Volume 9:Issue 48(2017)
• Page Start: 19271
• Page End: 19278
• Publication Date: 2017-11-30
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c7nr06354g
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Individually accessible polarization states in multilayer ferroelectric-insulator structures for multi-bit memories. Abstract : Here we report a ferroelectric capacitor structure obtained by alternating ferroelectric and insulator thin-film layers which allows an increase of up to 2 n polarization states, with n the number of ferroelectric layers. Four and up to eight distinct, stable and independently addressed polarization states are experimentally demonstrated in this work. The experimental findings are supported by a theoretical model based on the Landau–Ginzburg–Devonshire theory. The key parameter is the change in the strain conditions of ferroelectric layers induced by the insulating separator. Notably, the 2 n increase in the storage capacity can be achieved without major changes in the present technology used for FeRAM devices. The test structures demonstrate very good memory characteristics such as retention and fatigue, opening the way towards the design of high density ferroelectric memories.