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Exploring the unique physical properties of oxide perovskites necessitates their growth on diverse single‐crystal substrates. The thin‐film growth of perovskite SrMnO3 (SMO) has been a particular focus of research due to its emerging room‐temperature multiferroicity. Herein, the epitaxial thin films of (110)‐oriented SMO are grown on the piezoelectric (110)‐oriented (1–x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN‐PT) substrate. The effects of the thickness and oxygen annealing on the crystal structure, stoichiometry, and ferroelectric properties of the SMO thin film are systematically investigated. The tensile strain produced by the lattice mismatch between the bulk SMO and the PMN‐PT substrate causes an expansion of the c‐lattice parallel to the in‐plane direction of the substrate. The films show larger a‐, b‐, and c‐lattice parameters than the bulk material, resulting in volume expansion of the unit cell. This lattice expansion is attributed to the generation of oxygen vacancies driven by the reduced formation energy caused by the high elastic strain. Piezoelectric force microscopy reveals that the SMO film contains domains with strain‐mediated in‐plane and vacancy‐mediated out‐of‐plane polarization. Furthermore, the piezoelectric response of the PMN‐PT substrate effectively modulates the biaxial tensile strain in the SMO film, offering a potential strategy for controlling the crystal structure and ferroelectric properties of SMO. [ABSTRACT FROM AUTHOR]

Ferroelectricity in HfO2 thin films can be utilized for fast, power‐efficient, and highly scalable non‐volatile memories. However, the required wake‐up process for inducing ferroelectricity/ achieving higher polarization is one of the major hurdles that hinder HfO2‐based thin films from developing reliable electronic devices. The wake‐up effect is believed to originate from i) phase transformation from non‐ferroelectric to ferroelectric, ii) movement of defect entities (mainly oxygen vacancy defects) near the film‐electrode interface, and iii) heterogeneity of the electrode interfaces. In the present study, an experimental strategy is designed to overcome these sources of the wake‐up process. A multi‐step deposition and annealing process is carried out to induce wake‐up‐free ferroelectricity in Yttrium doped HfO2 (Y:HfO2) thin film directly grown on Si‐substrate. Furnace annealing is utilized instead of the standard rapid thermal annealing process to reduce the oxygen deficiencies and stimulate the direct growth of the polar Y:HfO2. The oxygen‐vacancy‐related defects are found to be the dominating source of wake‐up effect in Y‐doped HfO2 films. The step‐wise deposition and annealing in the oxygen atmosphere facilitate direct growth of the polar phase, reduce the oxygen vacancies, and induce wake‐up‐free ferroelectricity in Y:HfO2. [ABSTRACT FROM AUTHOR]

Hafnium zirconium oxide (HZO) has been studied intensively due to its potential application to memory and logic devices based on its outstanding dielectric and ferroelectric properties. Because many process factors can significantly impact the properties of HZO thin film, an optimized process or post‐treatment is necessary to ensure its performance. Herein, the effect of hydrogen on HZO thin film can make the film degraded. Analysis of the polarization–voltage hysteresis loops and I–V measurements indicate a leaky behavior in the film. To address this issue, post‐oxygen‐plasma treatment is performed on the film, which results in the decrease in hydrogen ions inside the film and consequently reduces the leakage current density. This finding can provide new insight into the effect of hydrogen incorporation for HZO thin films and methodology to remove leaky components inside ferroelectric films using O2 plasma treatment. [ABSTRACT FROM AUTHOR]

A 17 nm thick PbTiO3 (PTO) films were fabricated via PbO gas phase reaction with TiO2 starting layer in a sputtering chamber. The influence of deposition temperature of TiO2 on the piezoelectric properties of PTO thin films was investigated. The remnant piezoresponse of PTO films nonlinearly increased as a function of TiO2 deposition temperature, which is correlated with the increase in average grain diameter of PTO film. As grain size increases, the restriction on remnant piezoresponse imposed by the grain boundary via coupling between local strain and polarization becomes less pronounced, which results in the increase in remnant piezoresponse. Furthermore, we found that the vertical shift in piezoresponse hysteresis loops is closely related to the residual stress state. A strong correlation between the negative vertical shift and the residual tensile stress reveals that residual stress on the resulting PTO film contributed to the asymmetric piezoelectric property. [ABSTRACT FROM AUTHOR]

Pb(Zr[sub 0.52]Ti[sub 0.48])O[sub 3] (PZT) thin films were fabricated on Pt( 111)/TiO[sub x]/SiO[sub 2]/Si substrates at 375°C by radio frequency magnetron sputtering. A mixture of (110) and (100) orientations was found in all the PZT thin films. However, the in-plane grain size increased with an increase in film thickness, all films had smooth surfaces, and the root mean square roughness of the PZT films was in the range of 1-1.5 nm. As the film thickness increased, a decrease in residual stress and volume density of the PZT films was observed. PZT films become poorly crystallized with a decrease in film thickness. The magnitude of the maximum displacement from atomic force microscopy in local piezoresponse hysteresis mode increased from 187.25 ± 9.363 in 40 nm to 418.5 ± 20.925 in 152 nm. We suggest that the degradation in piezoelectric properties with a decrease in film thickness resulted from degradation of the crystallinity observed using transmission electron microscopy analysis, size effects derived from the grain size, and the residual stress evaluated using a laser reflectance method. [ABSTRACT FROM AUTHOR]

Presents a study which focused on YBa[sub2]Cu[sub3]O[sub7-x] superconductor thin films, which were deposited on LaAlO[sub3](100) single crystal substrates using a metalorganic chemical vapor deposition method. Condition in which the critical characteristics of the bridge-type junctions decreased; Description of an X-ray diffraction pattern of thin films deposited on the single crystal substrate; Composition of the diffraction pattern.

We investigated the surface potential of TiO2 single crystals using scanning probe microscopy (SPM) under different gas environment. The SPM tip-induced electrical stress resulted in reversal in the surface potential, Vsurf, polarity only in H2/Ar (ΔVsurf = 0.30 eV) and not in Ar and O2. Quantitative measurement of the influence of ambient gas on the surface potential led us to develop a model where the adsorbed oxygen molecules and oxygen vacancies interact to change their relative concentration leading to different surface potential in TiO2. These results will give us insights into ambient-dependent physical phenomena in oxide thin film nanostructures. [ABSTRACT FROM AUTHOR]

Information storage system that has a potentially ultrahigh storage density based on the principles of atomic force microscopy (AFM) has been developed. Micro-electro-mechanical systems (MEMS) technology plays a major role in integration and miniaturization of the standard AFM. Its potential application for ultrahigh storage density has been demonstrated by AFM with a piezoresponse mode to write and read information bits in ferroelectric Pb(ZrxTi1−x)O3 films. With this technique, bits as small as 40 nm in diameter have been achieved, resulting in a data storage density of simply more than 200 Gb/in2. Retention loss phenomenon has also been observed and investigated by AFM in the piezoresponse mode. Finally, local piezoelectric measurements of PZT films by different processing technologies are discussed in detail. [Copyright &y& Elsevier]

Multiferroic materials have driven significant research interest due to their promising technological potential. Developing new room‐temperature multiferroics and understanding their fundamental properties are important to reveal unanticipated physical phenomena and potential applications. Here, a new room temperature multiferroic nanocomposite comprised of an ordered ferrimagnetic spinel α‐LiFe5O8 (LFO) and a ferroelectric perovskite BiFeO3 (BFO) is presented. It is observed that lithium (Li)‐doping in BFO favors the formation of LFO spinel as a secondary phase during the synthesis of LixBi1−xFeO3 ceramics. Multimodal functional and chemical imaging methods are used to map the relationship between doping‐induced phase separation and local ferroic properties in both the BFO‐LFO composite ceramics and self‐assembled nanocomposite thin films. The energetics of phase separation in Li doped BFO and the formation of BFO‐LFO composites are supported by first principles calculations. These findings shed light on Li's role in the formation of a functionally important room temperature multiferroic and open a new approach in the synthesis of light element doped nanocomposites for future energy, sensing, and memory applications. [ABSTRACT FROM AUTHOR]

We studied polarization switching of 295 nm thick 〈111〉-oriented-Pb(Zr[SUB0.45]Ti[SUB0.55])O[SUB3] (PZT) thin-film capacitors through a polarization hysteresis loop and piezoelectric force microscopy (PFM) on top of the Pt electrode. Positive voltage pulses of 450 kV/cm and 2.5 ms were applied to the top as a poling pulse. Negative pulses ranging from -45 to -60 kV/cm at an interval of 3 kV/cm were applied to the top electrode. After each pulse, we performed PFM imaging by applying 17 kHz ac voltage of 1 V peak to peak to the bottom electrode while grounding the top one and the tip. The first-harmonic amplitude and phase of the tip vibration signal were mapped over the scanned area of 10 × 10μm[SUP2]. Subsequently, we measured the polarization hysteresis curve at 100 Hz after each domain image acquisition to estimate the volume fraction of switched polarization induced by the positive voltage pulses. We analyzed the areal fraction of switched domains as a function of pulse voltage from phase images and compared it with the volume fraction obtained from the hysteresis loops. Based on the evolution of domain images and the comparison plots of the areal and volume fractions of switched domains, we conclude that forward domain growth is a rate-limiting step during polarization reversal in 〈111〉-oriented-PZT thin-film capacitors. [ABSTRACT FROM AUTHOR]

Direct observation of polarization distribution at nanoscale by scanning force microscopy across partially etched Pb(Zr, Ti)O[sub 3] film ferroelectric capacitors with size 2 × 3 µm and preferential orientation (111) has revealed an anomalous polarization pattern characterized by polarization inversion in the center of the capacitor. This self-structured pattern is reproducible and independent on the spontaneous polarization orientation, but strongly influenced by the film texture and capacitor size. In particular, capacitors of the same texture with size 0.5 × 0.5 µm as well as capacitors with (100) preferential orientation of any size did not exhibit such anomalous polarization distribution. A tentative explanation consistent with the essential features of the observed polarization behavior in terms of strain-induced phase transition is discussed. [ABSTRACT FROM AUTHOR]

A correction to the article "Direct observation of fatigue in epitaxially grown Pb(Zr, Ti)O3 thin films using second harmonic piezoresponse force microscopy," that was published in the 2010 issue is presented.

Despite the significant advancements of dielectric materials, the energy density values of dielectric capacitors are extremely low compared to those of other energy storage systems, e.g., batteries and fuel cells. The deposition of solid solution of ferroelectric and paraelectric multicomponent thin films are the most widely used approach to enhance the energy density of dielectric capacitors; however, it is extremely difficult to determine the optimized composition ratio of two or three components. In this study, we develop ultrahigh energy density single-component Sn-doped BaTiO 3 (BTS) epitaxial thin film capacitors. An ultrahigh energy density of 92.5 J/cm3 and energy efficiencies above 78% were successfully achieved in (111)-oriented BTS epitaxial thin film capacitors. These excellent results were attributed to the formation of multi-nanodomains accompanied by delayed polarization saturation, low remnant polarization, high breakdown strength, and high cycling stability. Engineering multi-nanodomains through chemical doping and epitaxial orientation is a facile approach to develop energy-efficient ultrahigh energy density capacitors. This approach can be extended for the design of other single-component-based energy-efficient dielectric capacitors with ultrahigh energy density. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Tensile stress relaxation by the modulation of interfacial residual stress. • Residual stress modulation by controlling material properties and process temperature. • Coefficient of thermal expansion and elastic modulus control in the copolymer system. • Remaining barrier property after bending cycle with the tensile strain of 1.09 % • Developed thin film encapsulation system was successfully applied to OLED. Thin film encapsulation (TFE) is an essential component for reliable operation of organic electronic devices. However, the brittleness of inorganic layer in TFE must be resolved to secure the long-term stability of flexible/bendable devices. In this study, the robustness of the TFE in mechanical deformation is improved by harnessing such an interfacial residual stress. During fabrication of TFE by the alternating deposition of the organic layer via initiated chemical vapor deposition (iCVD) and inorganic Al 2 O 3 via atomic layer deposition (ALD), the lower process temperature of iCVD (30 ℃) than that of ALD (90 ℃) generates a residual stress at the organic/inorganic interface, which was optimized by controlling the organic layer thickness, coefficient of thermal expansion (CTE), and elastic modulus. In order to optimize the residual stress, a new type of copolymer layer was suggested in TFE, synthesized from cyclohexyl acrylate (CHA) and 1,3,5-trimethyl-1,3,5-trivinylcyclosiloxane (V3D3) monomers. The water vapor transmission rate (WVTR) of the fabricated TFE was 3.1 × 10-5 g/m2·day, which was fully retained by optimized residual stress after 1000 times of bending cycles with the bending radius of 2.3 R, corresponding to the tensile strain exceeding 1.09%. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the nano-scale tribological characteristics of PZT thin films (Pb(Zr x Ti1− x )O3: PZT) with various Zr/Ti ratios were investigated using an Atomic Force Microscope (AFM). The PZT thin films deposited by the sol–gel method were characterized by using an AFM, X-Ray Diffraction (XRD), and a nano-indentation technique. From the experimental results, the friction coefficient of the PZT thin film was found to be about 0.1–0.2 under a 0.1–10 μN normal force. It was determined that the wear rate of the PZT thin film was in the order of 10−8 mm3/N·cycle. Also, it was observed that the crystalline structure of the PZT was amorphized due to mechanical stress. [Copyright &y& Elsevier]