http://www.mdpi.com/journal/materials/special_issues/ferroelectric-piezoelectric/ Dear Colleagues, Ferroelectrics and multiferroics have recently emerged as perspective materials for information technology and data storage applications, as well as ideal model platforms for studying polarization-mediated phenomena on surfaces and interfaces. Fundamental studies of polarization dynamics and coupling between polarization and other functional properties requires these to be studied on the nanoscale using either material confinement in the form of thin films, nanowires, and nanodots, or field confinement by an SPM probe. This issue of Materials aims to summarize recent advances in ferroelectric and piezoelectric materials on the nanoscale, with the coverage ranging from synthesis, growth, and patterning, to nanofabrication and device fabrication. The contribution on recent advances in characterization both using SPM based methods as well as scattering and nanodevice structures are particularly welcome. Finally, we aim to broadly represent the less-conventional applications of ferroelectric and electromechanically active materials – from biologic piezo- and ferroelectrics to energy harvesting systems. Guest Editor Dr. Sergei V. Kalinin {snippet name="submission_info"} http://www.mdpi.com/1996-1944/4/4/651/ Magnetoelectric (ME) composites that simultaneously exhibit ferroelectricity and ferromagnetism have recently gained significant attention as evident by the increasing number of publications. These research activities are direct results of the fact that multiferroic magnetoelectrics offer significant technological promise for multiple devices. Appropriate choice of phases with co-firing capability, magnetostriction and piezoelectric coefficient, such as Ni-PZT and NZFO-PZT, has resulted in fabrication of prototype components that promise transition. In this manuscript, we report the properties of Ni-PZT and NZFO-PZT composites in terms of ME voltage coefficients as a function of frequency and magnetic DC bias. In order to overcome the problem of toxicity of lead, we have conducted experiments with Pb-free piezoelectric compositions. Results are presented on the magnetoelectric performance of Ni-NKN, Ni-NBTBT and NZFO-NKN, NZFO-NBTBT systems illustrating their importance as an environmentally friendly alternative. http://www.mdpi.com/1996-1944/4/4/651/ Wed, 06 Apr 2011 00:00:00 CEST Materials 2011-04-06 4 4 Review 651 702 1996-1944 Magnetoelectric Interactions in Lead-Based and Lead-Free Composites 2011-04-06 doi: 10.3390/ma4040651 Mirza Bichurin Vladimir Petrov Anatoly Zakharov Denis Kovalenko Su Chul Yang Deepam Maurya Vishwas Bedekar Shashank Priya http://www.mdpi.com/1996-1944/4/2/417/ The present paper reviews models of domain structure in ferroelectric crystals, thin films and bulk materials. Common crystal structures in ferroelectric materials are described and the theory of compatible domain patterns is introduced. Applications to multi-rank laminates are presented. Alternative models employing phase-field and related techniques are reviewed. The paper then presents methods of observing ferroelectric domain structure, including optical, polarized light, scanning electron microscopy, X-ray and neutron diffraction, atomic force microscopy and piezo-force microscopy. Use of more than one technique for unambiguous identification of the domain structure is also described. http://www.mdpi.com/1996-1944/4/2/417/ Wed, 16 Feb 2011 00:00:00 CET Materials 2011-02-16 4 2 Review 417 447 1996-1944 A Review of Domain Modelling and Domain Imaging Techniques in Ferroelectric Crystals 2011-02-16 doi: 10.3390/ma4020417 Prashant R. Potnis Nien-Ti Tsou John E. Huber http://www.mdpi.com/1996-1944/4/1/260/ We have investigated the role of the Ti–O Coulomb repulsions in the appearance of the ferroelectric state in BaTiO3 as well as the role of the Zn–O Coulomb repulsions in BiZn0.5Ti0.5O3, using a first-principles calculation with optimized structures. In tetragonal BaTiO3, it is found that the Coulomb repulsions between Ti 3s and 3p states and O 2s and 2p states have an important role for the appearance of Ti ion displacement. In BiZn0.5Ti0.5O3, on the other hand, the stronger Zn–O Coulomb repulsions, which are due to the 3s, 3p, and 3d (d10) states of the Zn ion, have more important role than the Ti–O Coulomb repulsions for the appearance of the tetragonal structure. Our suggestion is consistent with the other ferroelectric perovskite oxides ABO3 in the appearance of tetragonal structures as well as rhombohedral structures. http://www.mdpi.com/1996-1944/4/1/260/ Mon, 17 Jan 2011 00:00:00 CET Materials 2011-01-17 4 1 Review 260 273 1996-1944 Electronic and Structural Properties of ABO3: Role of the B-O Coulomb Repulsions for Ferroelectricity 2011-01-17 doi: 10.3390/ma4010260 Kaoru Miura Masaki Azuma Hiroshi Funakubo http://www.mdpi.com/1996-1944/3/12/5274/ We investigate the interfacial chemistry of secondary Fe2O3 phases formed in a BiFeO3 (BFO) layer in BFO/ La0.67Sr0.33MnO3 (LSMO)/SrTiO3 (STO) heterostructures. A combination of high-resolution spherical aberration corrected scanning TEM and spectroscopy results, reveals that specific chemical and crystallographic similarities between Fe2O3 and BFO, enable the BFO layer to form a facile host for Fe2O3. http://www.mdpi.com/1996-1944/3/12/5274/ Tue, 14 Dec 2010 00:00:00 CET Materials 2010-12-14 3 12 Article 5274 5282 1996-1944 Chemistry of the Fe2O3/BiFeO3 Interface in BiFeO3 Thin Film Heterostructures 2010-12-14 doi: 10.3390/ma3125274 Miryam Arredondo Quentin M. Ramasse Kashinath Bogle Valanoor Nagarajan http://www.mdpi.com/1996-1944/3/12/5236/ Synthesis by the hydrothermal method has various advantages, including low reaction temperature, three-dimensional substrate availability, and automatic polarization alignment during the process. In this review, powder synthesis, the fabrication of piezoelectric thin films, and their applications are introduced. A polycrystalline lead zirconate titanate (PZT) thin film was applied to a micro ultrasonic motor, and an epitaxial lead titanate (PbTiO3) thin film was estimated as a ferroelectric data storage medium. Ferroelectric and piezoelectric properties were successfully obtained for epitaxial PbTiO3 films. As lead-free piezoelectric powders, KNbO3 and NaNbO3 powders were synthesized by the hydrothermal method and sintered together to form (K,Na)NbO3 ceramics, from which reasonable piezoelectric performance was achieved. http://www.mdpi.com/1996-1944/3/12/5236/ Thu, 09 Dec 2010 00:00:00 CET Materials 2010-12-09 3 12 Review 5236 5245 1996-1944 Piezoelectric Materials Synthesized by the Hydrothermal Method and Their Applications 2010-12-09 doi: 10.3390/ma3125236 Takeshi Morita http://www.mdpi.com/1996-1944/3/12/5169/ The paper reviews the recent applications of piezoelectric materials in structural health monitoring and repair conducted by the authors. First, commonly used piezoelectric materials in structural health monitoring and structure repair are introduced. The analysis of plain piezoelectric sensors and actuators and interdigital transducer and their applications in beam, plate and pipe structures for damage detection are reviewed in detail. Second, an overview is presented on the recent advances in the applications of piezoelectric materials in structural repair. In addition, the basic principle and the current development of the technique are examined. http://www.mdpi.com/1996-1944/3/12/5169/ Mon, 06 Dec 2010 00:00:00 CET Materials 2010-12-06 3 12 Review 5169 5194 1996-1944 Applications of Piezoelectric Materials in Structural Health Monitoring and Repair: Selected Research Examples 2010-12-06 doi: 10.3390/ma3125169 Wen Hui Duan Quan Wang Ser Tong Quek http://www.mdpi.com/1996-1944/3/12/5007/ Outstanding electrical properties of solids are often due to the composition heterogeneity and/or the competition between two or more sublattices. This is true for superionic and superprotonic conductors and supraconductors, as well as for many ferroelectric materials. As in PLZT ferroelectric materials, the exceptional ferro- and piezoelectric properties of the PMN-PT ((1−x)PbMg1/3Nb2/3O3−xPbTiO3) solid solutions arise from the coexistence of different symmetries with long and short scales in the morphotropic phase boundary (MPB) region. This complex physical behavior requires the use of experimental techniques able to probe the local structure at the nanoregion scale. Since both Raman signature and thermal expansion behavior depend on the chemical bond anharmonicity, these techniques are very efficient to detect and then to analyze the subtitle structural modifications with an efficiency comparable to neutron scattering. Using the example of poled (field cooling or room temperature) and unpoled PMN-PT single crystal and textured ceramic, we show how the competition between the different sublattices with competing degrees of freedom, namely the Pb-Pb dominated by the Coulombian interactions and those built of covalent bonded entities (NbO6 and TiO6), determine the short range arrangement and the outstanding ferro- and piezoelectric properties. http://www.mdpi.com/1996-1944/3/12/5007/ Thu, 25 Nov 2010 00:00:00 CET Materials 2010-11-25 3 12 Article 5007 5028 1996-1944 Probing the Nanodomain Origin and Phase Transition Mechanisms in (Un)Poled PMN-PT Single Crystals and Textured Ceramics 2010-11-25 doi: 10.3390/ma3125007 Aneta Slodczyk Philippe Colomban http://www.mdpi.com/1996-1944/3/11/4950/ We have investigated ferroelectric-gate field-effect transistors (FeFETs) with Pt/SrBi2Ta2O9/(HfO2)x(Al2O3)1−x (Hf-Al-O) and Pt/SrBi2Ta2O9/HfO2 gate stacks. The fabricated FeFETs have excellent data retention characteristics: The drain current ratio between the on- and off-states of a FeFET was more than 2 × 106 after 12 days, and the decreasing rate of this ratio was so small that the extrapolated drain current ratio after 10 years is larger than 1 × 105. A fabricated self-aligned gate Pt/SrBi2Ta2O9/Hf-Al-O/Si FET revealed a sufficiently large drain current ratio of 2.4 × 105 after 33.5 day, which is 6.5 × 104 after 10 years by extrapolation. The developed FeFETs also revealed stable retention characteristics at an elevated temperature up to 120 °C and had small transistor threshold voltage (Vth) distribution. The Vth can be adjusted by controlling channel impurity densities for both n-channel and p-channel FeFETs. These performances are now suitable to integrated circuit application with nonvolatile functions. Fundamental properties for the applications to ferroelectric-CMOS nonvolatile logic-circuits and to ferroelectric-NAND flash memories are demonstrated. http://www.mdpi.com/1996-1944/3/11/4950/ Thu, 18 Nov 2010 00:00:00 CET Materials 2010-11-18 3 11 Review 4950 4964 1996-1944 Recent Progress of Ferroelectric-Gate Field-Effect Transistors and Applications to Nonvolatile Logic and FeNAND Flash Memory 2010-11-18 doi: 10.3390/ma3114950 Shigeki Sakai Mitsue Takahashi http://www.mdpi.com/1996-1944/3/11/4860/ Relaxors constitute a large class of ferroelectrics where disorder is introduced by doping with ions of different size and valence, in order to maximize their useful properties in a broad temperature range. Polarization disorder in relaxors is typically studied by dielectric and scattering techniques that do not allow direct mapping of relaxor parameters, such as correlation length or width of the relaxation time spectrum. In this paper, we introduce a novel method based on measurements of local vibrations by Piezoresponse Force Microscopy (PFM) that detects nanoscale polarization on the relaxor surface. Random polarization patterns are then analyzed via local Fast Fourier Transform (FFT) and the FFT PFM parameters, such as amplitude, correlation radius and width of the spectrum of spatial correlations, are mapped along with the conventional topography. The results are tested with transparent (Pb, La) (Zr, Ti)O3 ceramics where local disorder is due to doping with La3+. The conclusions are made about the distribution of the defects responsible for relaxor behavior and the role of the grain boundaries in the macroscopic response. http://www.mdpi.com/1996-1944/3/11/4860/ Thu, 28 Oct 2010 00:00:00 CEST Materials 2010-10-28 3 11 Article 4860 4870 1996-1944 Mapping Disorder in Polycrystalline Relaxors: A Piezoresponse Force Microscopy Approach 2010-10-28 doi: 10.3390/ma3114860 Andrei L Kholkin Dmitry A Kiselev Igor K Bdikin Andris Sternberg Brahim Dkhil Stephen Jesse Oleg Ovchinnikov Sergei V Kalinin http://www.mdpi.com/1996-1944/3/9/4550/ We review the pyroelectric properties and electronic structure of Li2B4O7(110) and Li2B4O7(100) surfaces. There is evidence for a pyroelectric current along the [110] direction of stoichiometric Li2B4O7 so that the pyroelectric coefficient is nonzero but roughly 103 smaller than along the [001] direction of spontaneous polarization. Abrupt decreases in the pyroelectric coefficient along the [110] direction can be correlated with anomalies in the elastic stiffness  contributing to the concept that the pyroelectric coefficient is not simply a vector but has qualities of a tensor, as expected. The time dependent surface photovoltaic charging suggests that surface charging is dependent on crystal orientation and doping, as well as temperature. http://www.mdpi.com/1996-1944/3/9/4550/ Wed, 01 Sep 2010 00:00:00 CEST Materials 2010-09-01 3 9 Review 4550 4579 1996-1944 The Electronic Structure and Secondary Pyroelectric Properties of Lithium Tetraborate 2010-09-01 doi: 10.3390/ma3094550 Volodymyr.T. Adamiv Yaroslav.V. Burak David. J. Wooten John McClory James Petrosky Ihor Ketsman Jie Xiao Yaroslav B. Losovyj Peter A. Dowben