1,721,278 research outputs found
Size Dependence Of Initial Polarization Direction In Nano-Sized Epitaxial PbTiO3 Islands Fabrication By Hydrothermal Epitaxy Below Tc
No full textSize dependence of initial polarization direction in nano-sized epitaxial PbTiO3 islands fabrication by hydrothermal epitaxy below Tc
No full textCHARACTERIZATION OF EPITAXIAL GROWTH OF PbTiO3 THIN FILMS ON (001) Nb-SrTiO3 FABRICATED BY HYDROTHERMAL SYNTHESIS METHOD
No full textCharacterizations of nanosized PbTiO3/Nb-SrTiO3 with scanning nonlinear dielectric microscopy
No full textCOMPATIBILITY AND CRYSTALLIZATION IN POLYNETHYLENE OXIDE)-POLY(METHYL METHACRYLATE) SEMIINTERPENETRATING POLYMER NETWORK
No full textDifferential scanning calorimetry together with dynamic mechanical analysis were employed to investigate the crystallinity and the miscibility in poly(ethylene oxide)/crosslinked poly (methyl methacrylate) semi-IPN (interpenetrating polymer networks). The crystallinity of poly(ethylene oxide) in the semi-IPN is found to depend on the crosslink density of PMMA as well as the overall content of PEO. Of special interest is that an increase in the crosslink density tends to increase the crystallinity contrary to our expectation, indicating crystallization and phase separation may proceed simultaneously during IPN formation. The investigation of glass transition behaviors with dynamic mechanical analysis suggests phase separation (i.e., there exist two amorphous phases: one PEO-rich phase, the other a PMMA-rich phase). (C) 1993 John Wiley Sons, Inc
Characterization of Nanosized PbTiO3/Nb-SrTiO3 with Scanning Nonlinear Dielectric Microscopy
No full textRetention loss behaviors in heteroepitaxial ferroelectric film with a +c monodomain fabricated by hydrothermal epitaxy below Tc
No full textWe observed the retention loss of dot domains (36 nm diameter) and square domains with sizes of 1 and 25 mu m(2) that were reversed by applying an electric field at an atomic force microscopy (AFM) conductive tip on a heteroepitaxial PbTiO3 thin film with + polarization in the virgin state, which was fabricated via hydrothermal epitaxy below T-c. Through theoretical calculations, it was discussed that the retention loss phenomena of a domain reversed by using an AFM tip were derived from the summation of the depolarization field energy and the strain-polarization coupling energy. Since the retention loss of the reversed domain with a straight c/c domain wall by applying a homogeneous electric field did not occur, we suggest that a cylindrical domain, which has a nearly straight c/c domain wall that extends to the bottom electrode on the given thin film, would be free from the retention loss. (c) 2006 American Institute of Physics.This work was supported by the Ministry of Science and Technology (M1010500066-01H2006400), the National Research Laboratory Program (M10400000024-04J0000-02410), and the Brain Korea 21 project of 2005
Size dependence of initial polarization direction in nanosized epitaxial PbTiO3 islands fabricated by hydrothermal epitaxy below Curie temperature
No full textNanosized epitaxial PbTiO3 (PTO) islands with a mono c domain were fabricated via self-assembly on a Nb-SrTiO3 (NSTO) substrate at 160 degrees C by hydrothermal epitaxy without undergoing the paraelectric to ferroelectric phase transition. The direction of the polarization at the as-fabricated state was observed with an island size up to a lateral area of 10(4) nm(2) and thickness of 12 nm (determined by atomic force microscope) using a piezoresponse force microscope. We found a critical size below which the negative polarization is stable at the as-fabricated state and above which the positive polarization is stable. This phenomenon was discussed under two assumptions: that the PTO islands are grown initially with positive polarization during fabrication, and the energy barrier for the transition from the positive polarization state to the negative polarization state is dependent on the ferroelectric island size. (c) 2005 American Institute of Physics.This work was supported by the Ministry of Science and Technology Grant No. M1010500066-01H2006400, the National Research Laboratory Program Grant No. M10400000024-04J0000-02410, and the Brain Korea 21 Project in 2004
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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