Effect of manganese doping on the size effect of lead zirconate titanate thin films and the extrinsic nature of ‘dead layers’

Abstract

Abstract:We have investigated the size effect in lead zirconate titanate (PZT) thin films with a range of manganese (Mn) doping concentrations. We found that the size effect in the conventional Pt/PZT/Pt thin-film capacitors could be systematically reduced and almost completely eliminated by increasing Mn doping concentration. The interfacial layer at the electrode-film interface appears to disappear almost entirely for the PZT films with ~2% Mn doping levels, confirmed by the fits using the conventional "in-series capacitor" model. Our work indicates that the size effect in ferroelectrics is extrinsic in nature, supporting the work by Saad et al. Other implications of our results have also been discussed. By comparing a variety of experimental studies in the literature we propose a scenario that the "dead layer" between PZT (or barium strontium titanate, BST) and metal electrodes such as Pt and Au might have a defective pyrochlore/fluorite structure (possibly with a small portion of ferroelectric perovskite phase).

Critical thickness for extrinsic contributions to the dielectric and piezoelectric response in lead zirconate titanate ultrathin films

“…This is attributed to the presence of an interfacial dead layer between the ferroelectric and metallic electrode, similar to what reported for other ferroelectric thin films, such as PZT, 32 Ba͑Zr 0.25 Ti 0.75 ͒O 3 , 28 and ͑Ba, Sr͒TiO 3 . This is attributed to the presence of an interfacial dead layer between the ferroelectric and metallic electrode, similar to what reported for other ferroelectric thin films, such as PZT, 32 Ba͑Zr 0.25 Ti 0.75 ͒O 3 , 28 and ͑Ba, Sr͒TiO 3 .…”

Sol–Gel Synthesis and Characterization of Na0.5Bi0.5TiO3–NaTaO3Thin Films

“…The dielectric properties of ferroelectric perovskite thin films are known to be influenced by many effects, such as grain size, grain boundaries, film thickness, etc . In general, a reduction in the thickness and the grain size leads to a decrease in the dielectric permittivity and an increase in the dielectric losses in thin films .…”

Effect of a built-in electric field in asymmetric ferroelectric tunnel junctions

“…Indeed, Lou and Wang found that the "dead layer" between Pt and Pb(ZrTi)O 3 is extrinsic and could be removed almost completely by doping 2% Mn. 59 Experimentally, many researchers found that SRO/BTO/SRO capacitors (as well as other perovskite FE structures with conductive oxide electrodes) are free from passive layers. 31,60,61 Recently, a very interesting experimental result demonstrates that the RuO 2 /BaO terminations at BTO/SRO interface, which is assumed as many pinned interface dipoles and plays a detrimental role in stabilizing a switchable FE polarization, can be overcome by depositing a very thin layer of SrTiO 3 between the BTO layer and SRO electrode.…”