Low-field Switching Four-State Nonvolatile Memory

Nature, Scientific Reports has published an article written by H. M. Yau, Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China, Z. B. Yan, Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China, N. Y. Chan, K. Au, C. M. Wong, C. W. Leung, Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China, F.Y. Zhang, X. S. Gao, Institute for Advanced Materials and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China,and J. Y. Dai, Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China.

(a) Low magnification TEM cross-section image of
5nm-BTO on LSMO grown on STO substrate;
(b) the corresponding electron diffraction pattern including
the STO substrate and BTO/LSMO layers;
(c) High-resolution TEM image of the NiFe/BTO/LSMO observed
along [100] direction; and (d) a noise-reduced image from (c).

Abstract : “Multiferroic tunneling junction based four-state non-volatile memories are very promising for future memory industry since this kind of memories hold the advantages of not only the higher density by scaling down memory cell but also the function of magnetically written and electrically reading. In this work, we demonstrate a success of this four-state memory in a material system of NiFe/BaTiO3/La0.7Sr0.3MnO3 with improved memory characteristics such as lower switching field and larger tunneling magnetoresistance (TMR). Ferroelectric switching induced resistive change memory with OFF/ON ratio of 16 and 0.3% TMR effect have been achieved in this multiferroic tunneling structure.”