@article{christman_kim_maiwa_maria_rodriguez_kingon_nemanich_2000, title={Spatial variation of ferroelectric properties in Pb(Zr-0.3, Ti-0.7)O-3 thin films studied by atomic force microscopy}, volume={87}, ISSN={["0021-8979"]}, DOI={10.1063/1.373492}, abstractNote={Imaging of the phase and magnitude of the piezoelectric strain in Pb(Zr0.3,β€ŠTi0.7)O3 (PZT) capacitors is performed with an atomic force microscope. The imaging reveals a significant spatial dependence of the ferroelectric properties of both fatigued and unfatigued PZT films. We propose that the variation is related to the domain structure of the PZT. Through the measurement of local piezoelectric hysteresis loops and imaging of the piezoelectric strain, areas are observed in fatigued PZT that exhibit hysteresis loops shifted along the polarization axis. In some regions of fatigued samples, the hysteresis loops are shifted such that both remanent points of the hysteresis curve have the same polarization direction. These results have important implications for the scalability of nonvolatile ferroelectric random access memory to higher device densities.}, number={11}, journal={JOURNAL OF APPLIED PHYSICS}, author={Christman, JA and Kim, SH and Maiwa, H and Maria, JP and Rodriguez, BJ and Kingon, AI and Nemanich, RJ}, year={2000}, month={Jun}, pages={8031–8034} } @article{maiwa_maria_christman_kim_streiffer_kingon_1999, title={Measurement and calculation of PZT thin film longitudinal piezoelectric coefficients}, volume={24}, ISSN={["1058-4587"]}, DOI={10.1080/10584589908215586}, abstractNote={The ferroelectric and piezoelectric properties of 2000 {angstrom} thick chemical solution deposited Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT) thin films were investigated. Several Zr/Ti ratios were studied: 30/70, 50/50 and 65/35, which correspond to tetragonal, near-morphotropic, and rhombohedral symmetries. In all samples, a {l_brace}111{r_brace}-texture is predominant. Longitudinal piezoelectric coefficients and their dc field dependence were measured using the contact AFM method. The expected trend of a maximum piezoelectric coefficient at or near to the MPB was not observed. The composition dependence was small, with the maximum d{sub 33} occurring in the tetragonal material. To explain the results, crystallographic texture and film thickness effects are suggested. Using a modified phenomenological approach, derived electrostrictive coefficients, and experimental data, d{sub 33} values were calculated. Qualitative agreement was observed between the measured and calculated coefficients. Justifications of modifications to the calculations are discussed.}, number={1-4}, journal={INTEGRATED FERROELECTRICS}, author={Maiwa, H and Maria, JP and Christman, JA and Kim, SH and Streiffer, K and Kingon, AI}, year={1999}, pages={139–146} } @article{maiwa_christman_kim_kim_maria_chen_streiffer_kingon_1999, title={Measurement of piezoelectric displacements of Pb(Zr, Ti)O-3 thin films using a double-beam interferometer}, volume={38}, ISSN={["0021-4922"]}, DOI={10.1143/jjap.38.5402}, abstractNote={The double-beam interferometric method is applied to measure the field-induced displacement of Pb(Zr, Ti)O3 thin films. The dc electric field dependence of the longitudinal piezoelectric coefficient (d33) response of Pb(Zr, Ti)O3 thin films deposited by metal organic chemical vapor deposition (MOCVD) was measured. Experimental d33 values were compared with coefficients calculated using a phenomenological approach and bulk parameters. Qualitative agreement was obtained between measured and calculated coefficients.}, number={9B}, journal={JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS}, author={Maiwa, H and Christman, JA and Kim, SH and Kim, DJ and Maria, JP and Chen, B and Streiffer, SK and Kingon, AI}, year={1999}, month={Sep}, pages={5402–5405} }