Studies of the Transports and Electrical Properties in Multiferroic Tunnel Junction
Abstract
A multiferroic tunnel junction (MFTJ) consists of metal or ferromagnetic electrodes separated by a ferroelectric (FE) or single phase multiferroics barrier. We have studied two different MFTJ configurations: (i) La0.67Sr0.33MnO3 (LSMO)/PbZr0.52Ti0.48O3 (PZT)/LSMO, (ii) Pt/Pb(Zr0.53Ti0.47)0.60 (Fe0.5Ta0.5)0.40 O3 (PTZFT)/LSMO. We have grown ultrathin films of about 3 to 7 nm of PZT on LSMO/(LaAlO3)0.3 (Sr2AlTaO6)0.7 (LSMO/LSAT) (001) substrates using by pulsed laser deposition technique. With similar technique and substrate, we have grown ultrathin films of 4.5 to 6 nm of PZTFT. The x-ray diffraction patterns of the heterostructures show only the (00 l) reflections corresponding to the LSAT substrate, PZT or PZTFT and LSMO layers. The Atomic force microscopy of PZT/LSMO/LSAT and PZTFT/LSMO/LSAT heterostructures shows that the average surface roughness was less than 1 nm. Piezo force microscopy of the ultrathin PZT and PZTFT films shows a clear and reversible out-of-plane phase contrast above +/- 3 V, which indicates the ferroelectric character of those thin films. The Current-Voltage (IV) characteristics of the PZT/LSMO films, with PZT barrier thickness between 7 to 3 nm showed nonlinear IV characteristics indicating tunneling mechanism. The resistance switching behavior was observed from low resistance state to high resistance state and vice versa by sweeping the voltage from negative to positive and back.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2014
- Bibcode:
- 2014APS..MARY49004B