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0.5Pb(Ni 1/3 Nb 2/3 )O 3 -0.35PbTiO 3 -0.15PbZrO 3 (PNNZT) thin films fabricated on Pt/Ti/SiO 2 /Si(100) substrate using pulsed laser deposition (PLD) technique is discussed in this work. The effect of substrate temperature ( T S ) on phase formation, microstructure, dielectric and ferroelectric properties of PNNZT thin films have been studied by varying the T S from 100 to 800 °C with an interval of 100 °C. A minimum T S of ~ 500 °C was required to obtain the pure perovskite phase while the best electrical properties are achieved at T S  = 800 °C. The relative permittivity (ε r ’)) and remnant polarization ( P r ) of the PNNZT thin films increased from 130 to 1510 and 13.7 to 18.5 μC/cm 2 (at 1 kHz), respectively with increasing T S from 500 to 800 °C, while the average grain size (GS) grew from 6 to 85 nm. The conductivity and impedance studies led to the understanding of electrical behavior of the deposited PNNZT thin films. The observed changes in electrical properties were ascribed to the grain growth with the increase in T S . [ABSTRACT FROM AUTHOR]

A dual phase system with different compositions (X = 0, 0.2, 0.4, 0.6, 0.8, 1.0) of (Bi 4 Ti 3 O 12 ) X –(CaCu 3 Ti 4 O 12 ) 1 − X , [(BTO) X –(CCTO) 1 − X ] thin films have been grown on a platinized silicon substrate using the spin-coating technique. The X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and Raman results show that the two different crystal phases, orthorhombic BTO and cubic CCTO exist together within the thin film matrices. The effect of BTO phase concentration on the dielectric and the P-E hysteresis behavior of the composites was investigated. In an unexpected observation, the incorporation of CCTO into BTO is found to enhance the dielectric constant of the nanocomposite, in accordance with the percolation theory. The ferroelectric hysteresis (P-E) loops were altered with relating to stoichiometry compositions. Near the percolation threshold for 20 mol% BTO with 80 mol% CCTO in composite, high dielectric constant (~ 6378), and high coercivity (~ 162 kV/cm) is obtained compared to the single phase BTO and CCTO. These results show that the (Bi 4 Ti 3 O 12 ) 0.2 –(CaCu 3 Ti 4 O 12 ) 0.8 is a good candidate for the miniaturization of modern microelectronic devices. [ABSTRACT FROM AUTHOR]

The integration of ferroelectric layers on gallium nitride (GaN) offers a great potential for various applications. Lead zirconate titanate (PZT), in particular Pb(Zr 0.52 Ti 0.48 )O 3 , is an interesting candidate. For that a suitable buffer layer should be grown on GaN in order to prevent the reaction between PZT and GaN, and to obtain PZT with a preferred orientation and phase. Here, we study pulsed laser deposited (100) rutile titanium oxide (R-TiO 2 ) as a potential buffer layer candidate for ferroelectric PZT. For this purpose, the growth, morphology and the surface chemical composition of R-TiO 2 films were analyzed by reflection high-energy electron diffraction, atomic force microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. We find optimally (100) oriented R-TiO 2 growth on GaN (0002) using a 675 °C growth temperature and 2 Pa O 2 deposition pressure as process conditions. More importantly, the R-TiO 2 buffer layer grown on GaN/Si substrates prevents the unwanted formation of the PZT pyrochlore phase. Finally, the remnant polarization and coercive voltage of the PZT film on TiO 2 /GaN/Si with an interdigitated-electrode structure were found to be 25.6 μC/cm 2 and 8.1 V, respectively. [ABSTRACT FROM AUTHOR]

Multiferroic pure, Ho doped, Mn doped, as well as Ho, Mn co-doped BiFeO 3 thin films were prepared using a sol–gel technique. The effect of Ho and Mn co-doping on the structure, ferroelectric and ferromagnetic properties of BiFeO 3 films was studied in detail. It shows that the enhanced ferroelectric polarization and magnetization were obtained after doping Ho and Mn. Such enhanced ferroelectric properties are attributed to ferroelectric distortion derived from the structural transformation and microstructure improvement after doping Ho and Mn. The enhanced ferromagnetic properties are attributed to the uncompensated surface spins and the release of the latent magnetization locked within the cycloid induced by doping Ho and Mn. The present work provides an easy method to enhance the ferroelectric and ferromagnetic properties of BiFeO 3 based magnetoelectric multiferroic films. [ABSTRACT FROM AUTHOR]

Na 0.5 Bi 0.5 TiO 3 (NBT) thin films were grown with oxygen gas pressure in the range of 5 Pa and 100 Pa. NBT thin film grown at 30 Pa shows improved properties when compared to films grown at other pressures. This film exhibits single phase and good crystallinity. It has the highest dielectric constant of 754 and lowest dielectric loss of 0.21 at 1 kHz. It has the lowest leakage current of 2 × 10 − 6 A/cm 2 measured at 50 kV/cm electric field. The values of remnant polarization and coercive field, which were measured at room temperature, 10 V and 1 kHz, are 20 μC/cm 2 and 160 kV/cm respectively. Fatigue study reveals that remnant polarization (+ Pr and − Pr) decreases by 15% after 10 8 switching cycles. [ABSTRACT FROM AUTHOR]

In the present work, Li-doped ZnO nanorods have been deposited onto SiO 2 glass substrates by the simple and economical Chemical Bath Deposition method. These layers were further characterized in terms of structural, morphological, dielectric and ferroelectric properties as a function of Li content. X-ray diffraction patterns revealed the highly c -oriented hexagonal wurtzite structure of the films. Both dielectric measurements and ferroelectric investigations at nano- and micro-scale pointed out the existence of a ferroelectric behavior in such doped ZnO nanostructures. This ferroelectric activity can be further enhanced by increasing the dopant content in the material. [ABSTRACT FROM AUTHOR]

Abstract: Magnetoelectric (ME) Ni/Pb(Zr0.52Ti0.48)O3 bilayers have been prepared by hydrothermal method. The structure and ferroelectric properties of the Pb(Zr0.52Ti0.48)O3 (PZT) thin films prepared at various hydrothermal temperatures are characterized by X-ray diffraction and ferroelectric testing. With the hydrothermal temperature increasing the grain size of the PZT thin films gradually decreases leading to a gradual increase of the coercive field and a decrease of the remnant polarization of the Ni/PZT bilayers. The ME voltage coefficient of the Ni/PZT bilayers gradually decreases as hydrothermal temperature increases. The large ME coefficient makes these Ni/PZT bilayers possible for applications in multifunctional devices such as electromagnetic sensor, transducers and microwave devices. [Copyright &y& Elsevier]

Abstract: Highly (001)-oriented 1mol% Mg doped (Ba0.67,Sr0.33)TiO3 (BST) films with a thickness of 1.25μm were grown on (110) SrRuO3/(001) SrTiO3 substrates by pulsed laser deposition. X-ray diffraction measurements reveal that the BST thick films have very high crystalline quality, and have a distorted lattice with a large tetragonality a/c =1.012. The BST thick films have a remanent polarization (P r ) value as large as 10.1μC/cm2 and a coercive electric field (E c ) value of 65.0kV/cm. The films possess dielectric constant and loss values of ε r =385.36 and tgδ =0.038 at 1kHz and room temperature. The leakage currents of the films are on the order of 10−5 A/cm2 at ±150kV/cm. The mechanism for enhancing electric properties of the Mg doped BST films was also discussed. [Copyright &y& Elsevier]

Abstract: BaTiO3 films were epitaxially grown on SrTiO3 (001) substrates buffered with SrRuO3 films as bottom electrode by pulsed laser deposition under high oxygen pressure of 30Pa. The quality of the BaTiO3/SrRuO3/SrTiO3 multilayer films was analyzed by means of X-ray diffraction, atomic force microscopy and transmission electron microscopy. BaTiO3 films were found to be highly c-axis-oriented tetragonal phase with c/a=1.002. The dielectric constant first increased with increasing temperature, and showed a peak at the Curie temperature of about 356K. The films had well-saturated hysteresis loops with a remnant polarization of 7.3μC/cm2 and a coercive field of 29.5kV/cm at room temperature. [Copyright &y& Elsevier]

Abstract: We report high dielectric tunabilities of (1−x)Ba(Zr0.2Ti0.8)O3 −x(Ba0.7Ca0.3)TiO3 (BZT–xBCT) (x=0.15, 0.30, 0.40, 0.45, 0.50, and 0.55) thin films prepared by a sol–gel method. The films show a pure perovskite structure with random orientation. They have moderate dielectric constant ranging from 350 to 500 and low dielectric loss near 3.0% at 1kHz with 0V bias at room temperature. The dielectric tunability of the BZT–0.55BCT thin films is up to 65% at 400kV/cm and 100kHz. The films exhibit a high optical transmission in the range of 420nm–1500nm. Their optical band gap energies are about 3.90eV. [Copyright &y& Elsevier]

Abstract: High quality epitaxial Bi3.15Nd0.85Ti3O12 (BNT) thin films with thicknesses from 30 to 80nm have been integrated on SiO2/Si substrates. MgO templates deposited by ion-beam-assisted deposition and SrRuO3 (SRO) buffer layers processed by pulsed laser deposition have been used to initiate the epitaxial growth of BNT films on the amorphous SiO2/Si substrates. The structural and ferroelectric properties were investigated. Microstructural studies by X-ray diffraction and transmission electron microscopy revealed high quality crystalline with an epitaxial relationship of (001)BNT||(001)SRO||(001)MgO and [100]BNT||[110]SRO||[110]MgO. A ferroelectric hysteresis loop with a remanent polarization of 3.1μC/cm2 has been observed for a 30nm thick film. The polarization exhibits a fatigue-free characteristic up to 1.44×1010 switching cycles. [Copyright &y& Elsevier]

Abstract: This work studies the impact of adding nanoparticles to high-k PMNT (lead magnesium niobate–lead titanate, Pb(Mg0.33Nb0.67)0.65Ti0.35O3) thin films. PMNT thin films were grown on Pt(111)/TiO2/SiO2/Si substrate using a sol–gel technique. Ligand stabilised PMNT nanoparticles were added to the sol–gel material with the aim of seeding the crystallization process. The measurements show that use of nanoparticles in PMNT thin films influences the remanent polarization, coercive field and dielectric constant. These characterization results support the ongoing investigation of the material ferroelectric and electrical properties which are necessary before the novel dielectric can be used in silicon applications. [Copyright &y& Elsevier]

Abstract: Ferroelectric Bi3.25La0.75Ti3O12 thin films annealed at different temperatures were prepared on Pt/Ti/SiO2/Si substrates by metalorganic decomposition method. The leakage current behavior and the current conduction mechanism were investigated. For all films, the leakage current density − electric field (J−E) characteristic is confined within a “triangle” in the log (J)− log (E) plane bounded by three limiting curves: Ohm''s law (J ∝ E), trap-filled-limit (J ∝ E a , a >1), and Child''s law (J ∝ E 2 ). At high field region, Bi3.25La0.75Ti3O12 thin films with grains of rod-like show higher leakage current, while films with grains of spherical- or planar-like exhibit lower leakage current. [Copyright &y& Elsevier]

Abstract: BaTiO3 (BTO) nano-films were implanted with iron by means of ion-implantation. According to the results of X-ray diffraction (XRD) and Raman analysis, all the films are single-phase with tetragonal structure. Upon the increase of Fe dosage, on one hand, there is a decrease in c/a ratio of the unit cells. As the grain size and surface roughness of the Fe-implanted films decrease, the well crystallized film was obtained. Consequently, both decreasing of coercivity and boosting of magnetization were observed simultaneously. With the decline of the grain size and surface roughness during thermal treatment of the Fe-implanted films, there is an improvement of Fe distribution across the BTO matrix. Consequently, there is a decrease of coercivity and rise of magnetization. Upon the decrease of Fe dosage, on the other, there is a decline in magnetization, and a ferroelectric hysteresis loop is observed at a Fe dosage of 3.0 × 1014 cm−2. Additionally, the dependence of capacitance on the applied magnetic field and its frequency were also monitored. [ABSTRACT FROM AUTHOR]

Abstract: Bismuth ferrite (BiFeO3, BFO) thin films were spin-coated on Pt/Ti/SiO2/Si substrates by a chemical solution deposition method. The ferroelectric BFO films annealed at 500°C and 550°C were found to possess unipolar resistive switching behaviors. The resistance ratio of the high resistance state (HRS) to the low resistance state (LRS) of the unipolar resistance switching is about 103 for the ferroelectric BFO films. The conduction mechanisms are concluded to be space charge-limited conduction for the initial state and Ohmic conduction for the LRS. As for the HRS, the Poole–Frenkel emission fits well in the whole voltage region. Traps composed of oxygen vacancies are considered to play a key role in forming conducting paths. The relaxation time of electronic carriers is much shorter than that of ionic oxygen vacancies; therefore, the resistance switching is considered more probably due to carrier injection and emission through the Poole–Frenkel model after forming. [ABSTRACT FROM AUTHOR]

Abstract: Homogeneous pore-free Ba2NaNb5O15, KSr2Nb5O15, and 2·Na2O–PbO–6·Nb2O5 thin films were fabricated on sapphire substrates using the sol–gel technique. By controlling the gelation and coating process, thickness of thin films fabricated was controllable from ~40nm to ~10μm. Synthesized thin films possessed highly preferred orientated microstructure. Another advantage of this method is the subsequent heat treatment temperature dramatically decreased compared with other methods. This increases stoichiometry control and makes the large scale fabrication more feasible and efficient. [ABSTRACT FROM AUTHOR]

Abstract: Magnetoelectric multiferroic Bi0.7Dy0.3FeO3 (BDFO) thin films deposited on p-type Si (100) substrate using pulsed laser deposition technique demonstrated a saturated ferroelectric and ferromagnetic hysteresis loop at room temperature. More interestingly, the observed change in electric polarization with applied magnetic field in these films indicated the presence of room temperature magnetoelectric coupling behavior. Using high-frequency capacitance–voltage measurements, the fixed oxide charge density, interface trap density and dielectric constant were estimated on Au/BDFO/Si capacitors. These results suggest the integrated circuit compatible application potential of BDFO films in the field of micro-electro-mechanical systems and non-volatile memories. [Copyright &y& Elsevier]

Abstract: We have grown and characterized BaZr0.2Ti0.8O3 (BZT) epitaxial thin films deposited on (001) and (111)-oriented SrRuO3-buffered SrTiO3 substrates by pulsed laser deposition. Structural and morphological characterizations were performed using X-ray diffractometry and atomic force microscopy, respectively. A cube-on-cube epitaxial relationship was ascertained from the θ–2θ and φ diffractograms in both (001) and (111)-oriented films. The (001)-oriented films showed a smooth granular morphology, whereas the faceted pyramid-like crystallites of the (111)-oriented films led to a rough surface. The dielectric response of BZT at room temperature was measured along the growth direction. The films were found to be ferroelectric, although a well-saturated hysteresis loop was obtained only for the (001)-oriented films. High leakage currents were observed for the (111) orientation, likely associated to charge transport along the boundaries of its crystallites. The remanent polarization, coercive field, dielectric constant, and relative change of dielectric permittivity (tunability) of (111)-oriented BZT were higher than those of (001)-oriented BZT. [Copyright &y& Elsevier]

Abstract: Lead-free piezoelectric thin films of NaNbO3–BaTiO3 were fabricated on Pt/TiO x /SiO2/Si substrates by chemical solution deposition. Perovskite NaNbO3–BaTiO3 single-phase thin films with improved leakage-current and ferroelectric properties were prepared at 650°C by doping with a small amount of Mn. The 1.0 and 3.0mol% Mn-doped 0.95NaNbO3–0.05BaTiO3 thin films showed slim ferroelectric P–E hysteresis and field-induced strain loops at room temperature. The 1.0 and 3.0mol% Mn-doped 0.95NaNbO3–0.05BaTiO3 films showed remanent polarization values of 6.3 and 6.2μC/cm2, and coercive field of 41 and 55kV/cm, respectively. From the slope of the field-induced strain loop, the effective piezoelectric coefficient (d 33) was found to be 40–60pm/V. [Copyright &y& Elsevier]

Abstract: Nanocrystalline barium strontium titanate (Ba x Sr1− x Ti1.02O3) thin films with a barium content of x =0.8, 0.9 and 1 have been fabricated in a metal–insulator–metal configuration on glass-planarized alumina substrates. Cost-effective processing measures have been utilized by using poly-crystalline alumina substrates, wet-chemical processing of the dielectric, and by a small physical area of the ferroelectric capacitors (as low as 50µm2 for radio frequencies measurements). Glass-planarization on alumina ceramic substrates enables barium strontium titanate films with high quality and homogeneity. We mainly focus on fine-tuning the electrical performance in the low gigahertz range (<10GHz). Extensive micro-structural and electrical characterization has been performed. Micro-structural information is obtained by: Transmission Electron Microscopy, Scanning Electron Microscopy and X-ray diffraction. The dielectric response is investigated as a function of temperature, frequency and electric field for each sample. We measured a relatively constant permittivity for typical operating temperatures of applications. The quality factor Q is between 21 and 27 at 1GHz at zero DC bias and the tuning ratio η between 1.8 and 2.2 at |E|=0.4MV/cm. [Copyright &y& Elsevier]

Abstract: Ti-modified thin films of multiferroic 0.72Bi(Fe1 − x Ti x )O3–0.28PbTiO3 (BFPT, x =0 and 0.02) solid solution were prepared by pulsed laser deposition. The BFPT (x =0 and 0.02) films possess a tetragonal structure with highly preferential (001) orientation. The effects of the ionic substitution on the properties of BFPT (x =0 and 0.02) films have been investigated. The leakage current of the BFPT (x =0.02) thin film is significantly reduced, and the dielectric and ferroelectric properties greatly improved by the aliovalent ionic substitution of Ti4+ for Fe3+. The BFPT (x =0.02) thin film exhibits a reasonably high remnant polarization P r with 2P r up to 90μC/cm2 at 312kV/cm and a switchable polarization up to 92μC/cm2 at 417kV/cm. [Copyright &y& Elsevier]

Abstract: Ferroelectric (Pb0.8,La0.1,Ca0.1)TiO3/Pb(Zr0.2,Ti0.8)O3 (PLCT/PZT) bilayered thin film was prepared on Pt(111)/Ti/SiO2/Si(100) substrate by RF magnetron sputtering technique. Pure perovskite crystalline phase, determined by X-ray diffraction, was formed in the PLCT/PZT bilayer. The bilayered film exhibited a very dense and smooth surface morphology with a uniform grain size distribution. The ferroelectric domain structures were investigated by a combination of vertical and lateral piezoresponse force microscopy (VPFM and LPFM, respectively). It is demonstrated by both VPFM and LPFM observations that out-of-plane and in-plane lamellar ferroelectric domains coexist in the bilayered thin film. The PLCT/PZT bilayered film possesses good ferroelectric properties with relatively high spontaneous polarization (2P s =82 µC/cm2) and remnant polarization (2P r =26.2 µC/cm2). [Copyright &y& Elsevier]

Abstract: Pb0.5Sr0.5TiO3 thin films were prepared on Pt/TiO2/SiO2/Si and LaNiO3 (LNO)/Si substrates by using chemical solution deposition technique, and a layer-by-layer annealing method was used in an attempt to improve the dielectric properties of the thin films. The structure, dielectric, and ferroelectric properties of the thin films were investigated. Improved dielectric properties of the thin films were clearly confirmed: the dielectric constant and dielectric loss for the films on Pt/TiO2/SiO2/Si substrates annealed at 650 °C were 1064 and 0.027, respectively, at 1 kHz, with a dielectric tunability of more than 50%; similarly, the films prepared on LNO/Si substrates, showed a high dielectric constant of 1280 and a low dielectric loss of 0.023, at 1 kHz. P–E hysteresis loop measurements indicated that the remanent polarization and coercive field for the films on Pt/TiO2/SiO2/Si substrates annealed at 650 °C were 15.7 μC/cm2 and 51 kV/cm, respectively. [Copyright &y& Elsevier]

Abstract: To develop high-performance piezoelectric films on conventional Pt(111)/Ti/SiO2/Si(100) substrates, sol–gel-derived highly [100]-textured Nb-doped Pb(ZrxTi1−x)O3 (PNZT) thin films with different Zr/Ti ratios ranging from 20/80 to 80/20 were prepared and characterized. The phase structure, ferroelectric and piezoelectric properties of the PZNT films were investigated as a function of Zr/Ti ratios, and it was confirmed that there was distinct phase transition of the PNZT system from tetragonal to rhombohedral when the Zr/Ti ratio varied across the morphotropic phase boundary (MPB). The Nb-doped PZT films showed enhanced remanent polarization but reduced coercive field, whose best values reached 75 μC/cm2 and 82 kV/cm, respectively at the composition close to MPB. In addition, the [100]-textured PNZT film at MPB also shows a high piezoelectric coefficient up to 161 pm/V. All these properties are superior to those for undoped PZT films. [Copyright &y& Elsevier]

Abstract: The BiFe1− x Mn x O3 (BFMO) (x =0.03, 0.05 and 0.07) thin films were deposited on indium tin oxide/glass substrates using a metal organic decomposition method. X-ray diffraction analysis reveals that the structure of BiFeO3 films is distorted somewhat by Mn substitution. The leakage measurements indicate that Mn doping content is a dominant factor affecting the leakage current of BFMO films. Due to the poor crystallinity, a small remanent polarization (P r) is observed in the BFMO x =0.05 thin film annealed using the conventional method. The P r values for the sequential-layer annealed BFMO films are found to be related to the intensity of (012) peak and the content of defect complexes between the oxygen vacancies and acceptors. [Copyright &y& Elsevier]

Abstract: BaTiO3 films were deposited on LaNiO3 buffered Si substrates with different LaNiO3 thickness. The LaNiO3 layer thickness dependence of the orientation, crystallinity, dielectric and leakage current properties for the BaTiO3 films was investigated. X-ray diffraction and scanning electron microscope results show that the increase of LaNiO3 thickness will improve the crystallization and grain size for the BaTiO3 films. Electrical measurements indicate that the BaTiO3 film grown on thicker LaNiO3 layer tends to exhibit higher dielectric constant, lower internal defect concentration and better insulating properties. The improved dielectric properties for BaTiO3 film on thicker LaNiO3 is suggested due to the combined result of improved electrical properties for LaNiO3 and improved microstructural properties for BaTiO3. [Copyright &y& Elsevier]

Abstract: Trilayered Bi3.25La0.75Ti3O12 (25 nm)/(Na0.5Bi0.5)0.94Ba0.06TiO3 (300 nm)/Bi3.25La0.75Ti3O12 (25 nm) and Pb(Zr0.4Ti0.6)O3 (25 nm)/(Na0.5Bi0.5)0.94Ba0.06TiO3 (300 nm)/Pb(Zr0.4Ti0.6)O3 (25 nm) thin films without undesirable phases have been deposited on Pt/Ti/SiO2/Si substrates. It was found that the Bi3.25La0.75Ti3O12 and Pb(Zr0.4Ti0.6)O3 layers are very effective to inhibit the charge transport in the trilayered films. Much better insulating properties than those of (Na0.5Bi0.5)0.94Ba0.06TiO3 films have been achieved in the trilayered films. The trilayered films show good dielectric, ferroelectric and pyroelectric properties. Remnant polarizations 2P r of 16 µC/cm2 and 34 µC/cm2, pyroelectric coefficients of 4.8×10− 4 C m−2 K−1 and 7.0×10− 4 C m−2 K−1 have been obtained for the Bi3.25La0.75Ti3O12/(Na0.5Bi0.5)0.94Ba0.06TiO3/Bi3.25La0.75Ti3O12 and Pb(Zr0.4Ti0.6)O3/(Na0.5Bi0.5)0.94Ba0.06TiO3/Pb(Zr0.4Ti0.6)O3 thin films, respectively. The trilayered films are promising candidates for sensor and actuator applications. [Copyright &y& Elsevier]

Abstract: Large area Ba1− x Sr x TiO3 (BST) thin films with x =0.4 or x =0.5 were deposited on 75 mm diameter Si wafers in a pulsed laser deposition (PLD) chamber enabling full-wafer device fabrication using standard lithography. The deposition conditions were re-optimized for large PLD chambers to obtain uniform film thickness, grain size, crystal structure, orientation, and dielectric properties of BST films. X-ray diffraction and microstructural analyses on the BST films grown on Pt/Au/Ti electrodes deposited on SiO2/Si wafers revealed films with (110) preferred orientation with a grain size <100 nm. An area map of the thickness and crystal orientation of a BST film deposited on SiO2/Si wafer also showed (110) preferred orientation with a film thickness variation <6%. Large area BST films were found to have a high dielectric tunability of 76% at an electric field of 400 kV/cm and dielectric loss tangent below 0.03 at microwave frequencies up to 20 GHz and a commutation quality factor of ~4200. [Copyright &y& Elsevier]

Abstract: Neodymium-doped lanthanum nickelate (La1− x Nd x NiO3, LNNO) thin films have been prepared on Si substrates by chemical solution deposition method. The effects of annealing temperature and the neodymium concentration on the structural and electrical properties of the thin films have been investigated. X-ray diffraction analysis showed that the LNNO thin films exhibited perovskite structure with (100) preferential orientation. The (100) orientation degree of the thin films changed with neodymium content; however, the resistivity of the thin films was not related to the degree of orientation. Field emission scanning electron microscopy observations confirmed that the films had a smooth surface and uniform thickness. The resistivity of the thin films annealed at 700 °C increased from 1.97 mΩ·cm to 5.35 mΩ·cm, with increasing neodymium doping amount from LaNiO3 to La0.6Nd0.4NiO3. [Copyright &y& Elsevier]

Abstract: Ferroelectric Ce2Ti2O7 films were grown with a pseudo-pyrochlore structure on an Y2O3/Si substrate by low-vacuum (6.664 Pa) anneal at 800 °C using chemical solution deposition. Trivalent state of Ce could be confirmed by using X-ray absorption-near-edge-structure. The dielectric constant at 1 MHz and dielectric loss of the film in the Pt/Ce2Ti2O7/Pt structure were measured as 48.7 and 0.013, respectively. A relatively large memory window of 1.24 V was measured with a Pt/Ce2Ti2O7/Y2O3/Si capacitor structure at an applied voltage of 6 V. The capacitance–voltage hysteresis was symmetrical without shift from the origin due to an effective suppression of the interfacial SiO2 formation under low-vacuum annealing conditions. The Ce2Ti2O7 film was compatible for application to a ferroelectric gate. [Copyright &y& Elsevier]

Abstract: A high throughput screening method was developed for automatic measurements of ferroelectric thin film samples with piezoresponse force microscopy. Libraries of samples with varying chemical compositions, produced with high throughput experimentation via the sol–gel route, were examined and piezoresponse images were recorded. A procedure was designed to calculate figures of merit that are related to the piezoelectric coefficient d 33. They were used to identify the most promising samples within a combinatorial library. The method was evaluated through comparison with macroscopic permittivity measurements. [Copyright &y& Elsevier]

Abstract: Lead zirconate–titanate Pb(Zr,Ti)O3 (PZT) capacitors with Pt bottom electrodes were prepared on MgO substrates by pulsed laser deposition (PLD) technique employing SrTiO3 (STO) template layer. Perovskite PZT thin films are prepared via stoichiometric target using the ultra-thin STO template layers while it is quite difficult to obtain the perovskite PZT on Pt electrode via stoichiometric target in PLD process. The PZT capacitor prepared with the STO template layer showed good hysteresis and leakage current characteristics, and it showed an excellent fatigue resistance. The ultra-thin STO template layers were characterized by angle-resolved X-ray photoelectron spectroscopy measurement. The effect of the STO template layer is discussed based on the viewpoint of the perovskite nucleation and diffusion of Pb and O atoms. [Copyright &y& Elsevier]

Abstract: In3+-added Bi4Ti3O12 films were deposited by the magnetron sputtering followed by annealing at 650 °C for crystallization. To obtain the ferroelectric performance, sputtering targets of the Bi2O3-In2O3-TiO2 system for In3+-added Bi4Ti3O12 films were systematically fabricated with varying In3+ and Bi3+ contents. The variations between the compositions of the targets and films were investigated. Analyses of structure, microstructure, composition, ferroelectricity, and electric properties were used to evaluate the In3+-added films. The films of In-0.1- and In-0.2-BInT (or Bi-0-BInT) obtained from the targets of Bi2.45In0.45Ti2.9O z and Bi2.45In0.55Ti2.9O z formed single phase after annealing. They had better remanent polarization of ∼7.0 μC/cm2 accompanied by a coercive field of ∼210 kV/cm, a dielectric constant of 133∼142 at 1 MHz, and a lower leakage current density of ∼10−8 A/cm2 at 75 kV/cm. The lower leakage current density was related to the drop of ion-jump conduction from the Ti4+ ↔Ti3+ transition. Although the indium substitution mainly occupying on the B or Ti site enhanced ferroelectricity by lattice distortion, it created oxygen vacancy to deteriorate ferroelectricity. [Copyright &y& Elsevier]

Abstract: Various crystallization parameters were studied during the fabrication of Bi3.15Nd0.85Ti3O12 (BNdT) thin films on Pt/Ti/SiO2/Si (100) by metal organic solution decomposition method. The effect of crystallization processes, crystallization ambients on the properties of BNdT thin films such as orientation, ferroelectric properties were examined. By adopting different fabrication processes, it is possible to get both highly c-axis oriented as well as randomly oriented thin films. Highly c-axis oriented BNdT thin film showed a large remnant polarization (2Pr) of 70 μC/cm2 at an applied voltage of 10 V and exhibited a fatigue free behavior unto 2×109 switching cycles. The improved ferroelectric properties of BNdT thin films suggest their suitability for high density ferroelectric random access memory applications. [Copyright &y& Elsevier]

Abstract: (100)-oriented 0.462Pb(Zn1/3Nb2/3)O3–0.308Pb(Mg1/3Nb2/3)O3–0.23PbTiO3 (PZN-PMN-PT) perovskite ferroelectric thin films were prepared on La0.7Sr0.3MnO3/LaAlO3 (LSMO/LAO) substrate via a chemical solution deposition route. The perovskite LSMO electrode was found to effectively suppress the pyrochlore phase while promote the growth of the perovskite phase in the PZN-PMN-PT film. The film annealed at 700 °C exhibited a high dielectric constant of 2130 at 1 kHz, a remnant polarization, 2P r, of 29.8 μC/cm2, and a low leakage current density of 7.2×10−7 A/cm2 at an applied field of 200 kV/cm. The ferroelectric polarization was fatigue-free at least up to 1010 cycles. Piezoelectric coefficient, d 33, of 48 pm/V was also demonstrated. The results showed that much superior properties could be achieved with the PZN-PMN-PT thin films on the solution derived LSMO electrode than on Pt electrode by sputtering. [Copyright &y& Elsevier]

Abstract: Thin films of potassium tantalate niobate KTa0.6Nb0.4O3 (KTN) were grown by pulsed laser deposition on five different substrates suitable for microwave devices: (100)MgO, (100)LaAlO3, (1–102)sapphire (R-plane), (0001)sapphire (C-plane) and alumina. The high volatility of potassium at the film growth temperature required the addition of an excess of potassium to the ablation target. For optimized deposition conditions, Rutherford backscattering showed that the KTN films had a 1: 1 atomic ratio for K:(Nb+Ta). As grown KTN thin films were single-phase, without any particular orientation on sintered alumina, whereas an epitaxial growth with the (100) orientation was achieved on (100)MgO and (100)LaAlO3 with a mosaicity Δω (100)KTN close to 0.7°–1.5° and ∼0.4°–0.9°, respectively, attesting a high crystalline quality. In contrast, growth of KTN on R-plane sapphire results in a texture with the (100) orientation and the presence of the (110) orientation as a secondary one. The room temperature measurements carried out on Au interdigited capacitors patterned on KTN coated (100) LaAlO3 and sapphire led at 1 GHz to an agility ΔC/C∼4.6% and ∼7.2%, respectively, for a moderate applied field of 15 kV cm−1. Stubs patterned on the same systems led to an agility ΔF r / F r of ∼2.2% and 4.2%, respectively, for F r =7 GHz and the same applied field. [Copyright &y& Elsevier]

Abstract: A direct patterning instrument and technique were developed that enabled direct fabrication of ceramic film patterns at room temperature, using laser beam activation of the interface between the substrate and an aqueous solution. It was shown that a crystallized BaTiO3 pattern could be fabricated on a titanium substrate with a laser pattern generator, without heat treatment afterwards. The BaTiO3 pattern had a line width of several tens of micrometers. The technique was also used to demonstrate the possibility of fabricating a TiO2 line, several micrometers wide, on a silicon wafer. [Copyright &y& Elsevier]

Abstract: Potassium niobate thin films were grown by pulsed laser deposition on various substrates. Influence of deposition conditions on film characteristics was studied. Structural investigation evidenced that single phase polycrystalline randomly oriented films were grown on sintered alumina whereas epitaxial films were grown on (100)SrTiO3 and (100)MgO substrates. The microstructure was highly controlled by the structural characteristics. Interdigited capacitors built from KNbO3 films on two different substrates (alumina and MgO) showed the strong influence of the structural characteristics on the dielectric behavior. The variation of the equivalent capacitance measured on the interdigital capacitor on MgO was 6.4% at 2.5 GHz while it was 1.5% on alumina, in both cases for a moderate applied field of ∼15 kV cm−1. The results show the potentiality of these ferroelectric materials for use in frequency agile microwave electronics. [Copyright &y& Elsevier]

Abstract: A model based on trapping and releasing of free carriers in band gap states located at the interfaces between electrodes and the ferroelectric film is used to explain the restoration of polarization which is sometimes observed. Experimental data on two kinds of polarization restoration in metal/ferroelectric/metal thin film structures are reported. The increase of polarization, which may be observed at the early stage of fatigue test, is attributed to the release of carriers which are trapped in interfacial states at the virgin state, before fatigue test. On the other hand, the previously reported “self recovery effect” is attributed to a competition between the strength of a trapped carrier–ferroelectric dipole interaction and the applied voltage which acts on the dipole orientation. [Copyright &y& Elsevier]

Abstract: In this paper, an Atomic Force Microscope (AFM) in the so-called piezoresponse mode is used to image the ferroelectric domains in radio frequency sputtered lithium niobate (LiNbO3) thin films. It is shown that ferroelectric domains are clearly detectable and most of the time confined in the grains. The vertical and the lateral motion of the vibration of the tip in response to the applied alternating voltage is recorded in order to reconstruct a cartography of the orientation of the ferroelectric domains, allowing us to observe the distribution of the orientation of the polarization in the polycrystalline film and providing additional information about the direction of the polarization, although it is not a fully 3D cartography. From Piezoresponse Force Microscopy images, it is clear that the dispersion of the orientation of the polarization vector in the studied LiNbO3 sample is very high. It is shown that the AFM quasi-3D mapping of the distribution of orientation in the material provides a valuable information and may help understanding the fundamental phenomena which govern the growth of the material. [Copyright &y& Elsevier]

Abstract: Chemically synthesized (Bi3.15Nd0.85)Ti3O12 (BNT) films annealed at 650 °C for 15 min were prepared by different approaches to improve their fatigue problem. These approaches involved the selection of substrates with different overlayers, the addition of hydrogen peroxide (H2O2) to a spin-coating solution, and annealing in different atmospheres. BNT films on Ti-overlayered substrates had performed badly if processed at oxidation environments. BNT films on TiO2-overlayered substrates displayed stable and unchanged fatigue endurance if the spin-coating solution was modified by drops of the H2O2 solution to lesson the formation of oxygen vacancies in crystalline films. They were also fatigue-free in ferroelectricity after 1010 switching cycles and had remanent polarization of 24 μm/cm2, coercive field of 52 kV/cm, nonvolatile charge density of 13 μC/cm2 during relaxed fatigue tests, and leakage current of 10−6 A at 3 V. [Copyright &y& Elsevier]

Abstract: Ferroelectric/shape memory alloy thin film multilayered heterostructures possess both sensing and actuating functions and are considered to be smart. In this article, Pb(Zr0.52Ti0.48)O3 (PZT) ferroelectric thin films and Ti-riched TiNi shape memory alloy thin films have been deposited on Si and SiO2/Si substrates in the 400–600 °C temperature range by pulsed laser deposition technique. Deposition processing, microstructure and surface morphology of these films are described. The TiNi films deposited at 500 °C had an austenitic B2 structure with preferred (110) orientation. The surfaces of the films were very smooth with the root-mean-square roughness on a unit cell level. The structure of the TiNi films had a significant influence on that of the subsequently deposited PZT films. The single B2 austenite phase of the TiNi favored the growth of perovskite PZT films. The PZT/TiNi heterostructures with the PZT and TiNi films respectively deposited at 600 and 500 °C exhibited a polarization-electric field hysteresis behavior with a leakage current of about 2×10−6 A/cm2. [Copyright &y& Elsevier]

Abstract: La- or Nd-substituted bismuth titanate (BLT or BNT) and Nb-cosubstituted bismuth titanate (Nb-BLT or Nb-BNT) thin films were prepared in the presence of nonionic surfactants, poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (EO x PO y EO x ) triblock copolymers, added as additives to the sol solution. For Nb-BLT films prepared with EO106PO70EO106, the (200) orientation relative to (117) was dominant as compared with Nb-BLT films produced without surfactant or with EO20PO70EO20, and the remanent polarization (P r) of the Nb-BLT film was 22 μC/cm2, which was superior to 10 and 15 μC/cm2 of Nb-BLT films prepared without surfactant or with EO20PO70EO20. The additional Nb cosubstitution in BLT and BNT affected particle orientation in the films and resulted in higher ferroelectricity than those of the BLT and BNT films. The Nb-BNT/EO106PO70EO106 film showed the best ferroelectric properties; its remanent polarization was 30 μC/cm2 and the polarization (P*–P˄) shows no significant change up to 8×108 switching cycles. [Copyright &y& Elsevier]

Abstract: Several methods have been used to prepare ferroelectromagnetic BiFeO3 films. In this paper, we adopted a sol–gel process to fabricate BiFeO3 films on indium tin oxide (ITO)/glass substrates. X-ray diffraction pattern indicated that the samples are randomly oriented. Cross section scanning microscopy showed that the thicknesses of both films were about 1.2 μm and no apparent diffusion between the BiFeO3 films and ITO/glass substrates. Remnant polarization of 2.0 and 1.75 μC/cm2 were identified by the measuring of electric hysteresis loops for the films annealed at 500 and 600 °C respectively at an applied field of 108 kV/cm. Dielectric property and loss factor were investigated as a function of frequency. In addition, magnetism was detected at 77 K. [Copyright &y& Elsevier]

Abstract: Oxygen-plasma treatment has been done on Bi3.25La0.85Ti3O12 (BLT) films for lower crystallization temperatures and improved ferroelectric properties. The films, prepared by metal organic decomposition method on Pt and IrO2 electrodes sputtered on Al2O3/SiO2/Si substrates, were pre-annealed at the relatively low temperatures of 550 and 600 °C, followed by room temperature microwave oxygen-plasma treatment. The oxygen-plasma-treated BLT films showed very good ferroelectric characteristics after a final furnace annealing at 600 °C. [Copyright &y& Elsevier]

Abstract: A chelating and spin-coating procedure was used to prepare antiferroelectric thin films of Pb0.99Nb0.02[(Zr0.84Sn0.16)0.982Ti0.018]0.98O3. By controlling substrate and thermal processing conditions, films with strong (100) and (111) textures, as well as without textures, were prepared. These antiferroelectric films showed the characteristic double hysteresis polarization vs. electric field loops. An orientation dependence of the critical field for the antiferroelectric-to-ferroelectric phase transition was also observed. In addition, when the applied voltage exceeded a critical level during the first “ramp up,” an abnormal reduction in the area of the hysteresis loop was noticed in the (100) and (111) textured films. [Copyright &y& Elsevier]

Abstract: Several crystallization parameters were studied during the fabrication of Bi3.5La0.5Ti3O12 thin films by means of a new aqueous chemical solution deposition method. Their effect on the microstructure, orientation, crystal structure and ferroelectric properties of the thin films was examined using scanning electron microscopy, X-ray and electron back-scattering diffraction and ferroelectric hysteresis loop measurements. The thermal treatment was optimized by applying an intermediate crystallization step for each layer, which led to the formation of dense films with ferroelectric properties. Without this intermediate crystallization, the films were shortcircuited due to the high porosity. Subsequently, the effect of the crystallization temperature on Bi3.5La0.5Ti3O12 thin films prepared from precursors containing 10 mol% Bi3+ excess, was looked into. The P r increased linearly with the crystallization temperature between 600 and 700 °C. Finally, the concentration of O2 in the ambient during the crystallization was varied. Hillocking occurred below 10% O2 due to a reaction of the substrate. The ferroelectric properties also deteriorated when crystallization was carried out below a critical O2 partial pressure. [Copyright &y& Elsevier]

Abstract: Yttrium substituted Bi4−x Y x Ti3O12 (x =0.00, 0.10, 0.30, 0.50, 0.75, 1.00) polycrystalline thin films were synthesized by metal-organic decomposition method. Ferroelectric measurements revealed that the Bi4Ti3O12 (BTO) films substituted by Y with appropriate ratios could have higher remnant polarization and significantly improved fatigue behavior compared with BTO. The remnant polarization of the Bi3.50Y0.50Ti3O12 capacitor reached 10 μC/cm2 at an applied field about 120 kV/cm with nearly fatigue free property up to 1010 cycles. By using Raman spectra, X-ray diffraction, and scanning electron microscope to analyze the structure and composition of the films, it was found that the Y substitution of Bi at A-site induces changes in film orientation and the lattice distortion that are probably responsible for the improved ferroelectric properties. The microstructure and its relation with the leakage behavior of these thin films were also discussed. [Copyright &y& Elsevier]

Abstract: Ferroelectric Sr0.7Bi2.1Ta2.0O9 thin films with a thickness of 200 nm were deposited on Pt(111)/Ti/SiO2/Si(100) substrate by means of the liquid delivery metal organic chemical vapor deposition process. The optimum substrate temperature and reactor pressure were 570 °C and 0.65 kPa, respectively. After depositing the thin films under optimum conditions, they were furnace-annealed at various temperatures for 1 h in oxygen ambient. Then a Pt top electrode was deposited by sputtering and the thin films were post-annealed in oxygen ambient, in order to improve their electrical properties. The surface morphology of the strontium bismuth tantalite (SBT) thin films deposited under optimum conditions showed the presence of pseudo-spherical particles and rod-shaped grains. The grains of the SBT thin films exhibited increasing growth of a layered perovskite phase with increasing annealing temperature. The remanent polarization values (2P r) of the SBT thin film annealed at 780 °C were 7.247 and 8.485 μC/cm2 at applied voltage of 3 V and 5 V, respectively. [Copyright &y& Elsevier]

Abstract: In this study, we examine the growth conditions for Pb0.92La0.08Zr0.4Ti0.6O3 thin films with a linear electro-optical response. Films grown on SrTiO3(100) substrate show good crystalline quality and surface smoothness, if deposited within a narrow range of substrate temperatures around 530 °C. Such films had a (002) rocking curve full width at half maximum less than 0.2°, and a surface roughness less than 0.4 nm. X-ray photoelectron spectroscopy analysis confirmed the absence of surface impurity phases and revealed a single oxidation state for Pb2+, Zr4+, and Ti4+cations. Good crystalline quality and a smooth film surface are required for the use of these materials in optical device applications. [Copyright &y& Elsevier]