Papers by Keyword: Pb(Zr,Ti)O₃

Abstract: We investigated domain structures in Pb(Zr,Ti)O₃ (PZT) ceramics whose composition lies on the morphotropic phase boundary (MPB) using transmission electron microscopy (TEM) and evaluated the piezoelectric properties of PZT. We found that monoclinic nanosized domains (nanodomains), which form in tetragonal domains, strongly correlated with the piezoelectric properties of PZT. The degree of formation of nanodomains depends on the grain composition. Thus, controlling the homogeneity of grain composition in the ceramics is crucial for optimizing the piezoelectric properties of PZT.

Abstract: Magnetoelectric(ME) coupling in multi-ferroic composite designed by using two material elements of Pb(Zr, Ti)O3 (PZT: 260μm) and magnetostrictive alloys(Galfenol based Fe-Ga-X(X=Al, Co), ferromagnetic shape memory Fe-Pd) was investigated. Output ME Voltage under the driving a.c.magnetic field Hac at f = 1 Hz in Fe81Ga19/PZT/ Fe81Ga19, Fe80Ga15Al5 /PZT/ Fe80Ga15Al5, Fe76Ga17Co7/PZT/ Fe76Ga17Co7 composites, in which the magnetostrictive foils(50μm thickness) were prepared by rapid solidification, increased in proportion to the actuated force than the magnetostriction.Moreover，output ME Voltage in Fe70Pd30 / PZT/ Fe70Pd30 laminates, in which the Fe70Pd30 films (10μm thickness) on PZT were deposited by sputtering method, exhibited 8 V at Hac of 175Oe, which is larger than 7.16 V for Fe76Ga17Co7 (50μm)/PZT/ Fe76Ga17Co7 (50μm) composites

Abstract: Full-dense bulk Pb(Zr,Ti)O3 (PZT) ceramics with various grain sizes were prepared by aerosol deposition (AD) employing various firing temperature from 800 to 1200°C. It was confirmed that the Hall-Petch relationship is obeyed in AD-processed PZT ceramics over the almost whole grain size range, which is indicating that only grain size could be the determining factor of hardness in AD since density is almost constant against the grain size. As compared with conventional sintering technique, AD-processed PZT ceramics exhibited higher hardness and higher or at least equivalent electrical properties over the whole grain size range investigated, which is indicating that the piezoelectric ceramics with improved mechanical properties can be realized by AD without any sacrifice in electrical properties.

Abstract: Pb(Zr, Ti)O3 thin films were successfully prepared on (111)Pt/IrO2/SiO2/(100)Si substrates using SrTiO3 seeds at 290 oC by RF inductive heating type and 350 oC by resistive heating type metalorganic chemical vapor deposition method (MOCVD), respectively. The SrTiO3 was chosen as seed layers and prepared by pulsed laser deposition method. The crystal structures and orientations of SrTiO3 seeds were changed by deposition temperature. In the case of preparation with RF inductive heating MOCVD, the remanent polarization (2Pr) and coercive field (2Ec) were 42 μC/cm2 and 256 kV/cm, respectively.

Abstract: Three types of bottom electrodes were deposited by RF magnetron sputtering on SiO2/Si substrates: LaNiO3 (LNO), Pt/Ti and LNO/Pt/Ti. The effect of different deposition and processing conditions for the LNO films on the ferroelectric properties of sputtered Pb(Zr0.52Ti0.48)O3 (PZT) capacitors was investigated. The LNO films were either deposited at room temperature and heattreated in O2 flow in the furnace at 500 or 600°C or made in situ in the range of 200-500°C. Other deposition parameters under study were the pressure, the RF power and the Ar:O2 ratio. The resistivity of the LNO films was measured and on some of the films with the lower values, amorphous PZT was deposited and then crystallized in the furnace. X-ray diffraction results show that the PZT films deposited over Pt/Ti had a preferential (100) orientation, while those deposited over LNO made in situ are strongly (100) oriented and the ones deposited over amorphous LNO do not exhibit any preferential orientation. The remanent polarization of the capacitors was around 28μC/cm2 when amorphous LNO or Pt/Ti electrodes were used and around 20μC/cm2 with LNO made in situ. Leakage currents were improved when LNO electrodes made in situ was used; a good ferroelectric fatigue performance of the capacitors when subjected to 1010 switching cycles was also observed