@article{maruyama_baure_jones_nikkel_moharam_craciun_mihai_pantelica_jones_nino_2019, title={Effect of Pt3Pb on the permittivity and conductivity of lead zirconate titanate thin films}, volume={685}, ISSN={["0040-6090"]}, DOI={10.1016/j.tsf.2019.06.041}, abstractNote={The evolution and interaction of buried interfaces during the synthesis of lead zirconate titanate (PZT) ferroelectric thin film devices have been previously predicted by density functional theory modeling and observed experimentally via in–situ structural characterization. Moreover, the formation and disappearance of an intermetallic phase (Pt3Pb) during the crystallization of the film has been identified as a key process expected to affect the resulting electrical properties of the devices. To elucidate this effect, a combination of direct current (leakage current measurements) and alternating current (impedance spectroscopy) characterization techniques are used to examine the electrical properties of sol–gel–derived PZT thin films. Films with the intermetallic phase exhibit a high potential barrier at the metal–insulator interface (0.83 eV) similar to the fully crystallized films (0.81 eV) and a lower current density than the films without the intermetallic phase, as shown in the Richardson plot. Impedance measurements also revealed that the conductivity of the films with the intermetallic phase, σ = 1.9 × 10−11 S cm−1, and the real part of the relative permittivity at 10 kHz, εr′=42, are lower than the other films (fully crystallized film: σ = 3.5 × 10−10 S cm−1 εr′=566, amorphous crystallized film: σ = 4.6 × 10−11 S cm−1 εr′=121). It is shown that these electrical characterization methods can serve as non–destructive examination tools to track the evolution of secondary phases during device synthesis and fabrication.}, journal={THIN SOLID FILMS}, author={Maruyama, Hiraku and Baure, George and Jones, Tarielle and Nikkel, Jason and Moharam, Marwa Mostafa and Craciun, Valentin and Mihai, Maria-Diana and Pantelica, Dan and Jones, Jacob L. and Nino, Juan C.}, year={2019}, month={Sep}, pages={420–427} }
 @article{mangum_podowitz-thomas_nikkel_zhou_jones_2017, title={Investigating Pb diffusion across buried interfaces in Pb(Zr0.2Ti0.8)O-3 thin films via time-of-flight secondary ion mass spectrometry depth profiling}, volume={49}, ISSN={["1096-9918"]}, DOI={10.1002/sia.6255}, abstractNote={The diffusion of Pb through Pb(Zr0.2Ti0.8)O3(PZT)/Pt/Ti/SiO2/Si thin film heterostructures is studied by using time‐of‐flight secondary ion mass spectrometry depth profiling. The as‐deposited films initially contained 10 mol% Pb excess and were thermally processed at temperatures ranging from 325 to 700°C to promote Pb diffusion. The time‐of‐flight secondary ion mass spectrometry depth profiles show that increasing processing temperature promoted Pb diffusion from the PZT top film into the buried heterostructure layers. After processing at low temperatures (eg, 325°C), Pb+ counts were low in the Pt region. After processing at elevated temperatures (eg, 700°C), significant Pb+ counts were seen throughout the Pt layer and into the Ti and SiO2 layers. Intermediate processing temperatures (400, 475, and 500°C) resulted in Pb+ profiles consistent with this overall trend. Films processed at 400°C show a sharp peak in PtPb+ intensity at the PZT/Pt interface, consistent with prior reports of a Pt3Pb phase at this interface after processing at similar temperatures.}, number={10}, journal={SURFACE AND INTERFACE ANALYSIS}, author={Mangum, John S. and Podowitz-Thomas, Stephen and Nikkel, Jason and Zhou, Chuanzhen and Jones, Jacob L.}, year={2017}, month={Oct}, pages={973–977} }
 @article{chung_fancher_isaac_nikkel_hennig_jones_2017, title={Temperature dependence of field-responsive mechanisms in lead zirconate titanate}, volume={100}, ISSN={["1551-2916"]}, DOI={10.1111/jace.14979}, abstractNote={Abstract An electric field loading stage was designed for use in a laboratory diffractometer that enables in situ investigations of the temperature dependence in the field response mechanisms of ferroelectric materials. The stage was demonstrated by measuring PbZr 1− x Ti x O 3 ( PZT ) based materials—a commercially available PZT and a 1% Nb‐doped PbZr 0.56 Ti 0.44 O 3 ( PZT 56/44)—over a temperature range of 25°C to 250°C. The degree of non‐180° domain alignment (η 002 ) of the PZT as a function of temperature was quantified. η 002 of the commercially available PZT increases exponentially with temperature, and was analyzed as a thermally activated process as described by the Arrhenius law. The activation energy for thermally activated domain wall depinning process in PZT was found to be 0.47 eV . Additionally, a field‐induced rhombohedral to tetragonal phase transition was observed 5°C below the rhombohedral‐tetragonal transition in PZT 56/44 ceramic. The field‐induced tetragonal phase fraction was increased 41.8% after electrical cycling. A large amount of domain switching (η 002 =0.45 at 1.75 kV/mm) was observed in the induced tetragonal phase.}, number={9}, journal={JOURNAL OF THE AMERICAN CERAMIC SOCIETY}, author={Chung, Ching-Chang and Fancher, Chris M. and Isaac, Catherine and Nikkel, Jason and Hennig, Eberhard and Jones, Jacob L.}, year={2017}, month={Sep}, pages={4352–4361} }
 @article{lin_chernatynskiy_nikkel_bulanadi_jones_nino_sinnott_2016, title={Diffusion Across M/Pb(Zr,Ti)O-3 Interfaces (M=Pt3Pb or Pt) Under Different System Conditions}, volume={99}, ISSN={["1551-2916"]}, DOI={10.1111/jace.13966}, abstractNote={Interfaces between functional ceramics, such as Pb(Zr0.5Ti0.5)O3 or PZT, and metal electrodes, such as Pt, are important for many devices. Maintaining an interface that is free of secondary phases is necessary for the efficient transfer of electrons and device function. However, there are instances where unstable transient phases form at the interface due to atomic diffusion, such as Pt3Pb. Here, we investigate the migration barriers for the diffusion of Pb across the PZT/Pt and PZT/Pt3Pb interfaces using density functional theory (DFT) and the climbing image nudge elastic band (c-NEB) method. Our calculation models take into account the influence of atmospheric conditions on Pb diffusion through the preferential stabilization of defects near the interface as a result of changes to the Pb and O chemical potentials. In addition, the PZT structures that are stable above and below the Curie temperature are considered. The migration barriers are predicted to be strongly dependent on atmospheric conditions and the phase of the PZT, tetragonal or cubic. In particular, an inversion of the Pb diffusion direction at the PZT/Pt interface is predicted to take place as the oxygen partial pressure increases. This prediction is confirmed by experimental in situ X-ray diffraction measurements of a PZT/Pt interface.}, number={1}, journal={JOURNAL OF THE AMERICAN CERAMIC SOCIETY}, author={Lin, Fang-Yin and Chernatynskiy, Aleksandr and Nikkel, Jason and Bulanadi, Ralph and Jones, Jacob L. and Nino, Juan C. and Sinnott, Susan B.}, year={2016}, month={Jan}, pages={356–362} }
 @article{jones_lebeau_nikkel_oni_dycus_cozzan_lin_chernatynskiy_nino_sinnott_et al._2015, title={Combined experimental and computational methods reveal the evolution of buried interfaces during synthesis of ferroelectric thin films}, volume={2}, number={10}, journal={Advanced Materials Interfaces}, author={Jones, J. L. and LeBeau, J. M. and Nikkel, J. and Oni, A. A. and Dycus, J. H. and Cozzan, C. and Lin, F. Y. and Chernatynskiy, A. and Nino, J. C. and Sinnott, S. B. and et al.}, year={2015} }