Accession Number : ADA605539


Title :   Smart Core-Shell Nanowire Architectures for Multifunctional Nanoscale Devices


Descriptive Note : Final rept. 1 Mar 2008-31 Aug 2013


Corporate Author : DREXEL UNIV PHILADELPHIA PA


Personal Author(s) : Spanier, Jonathan E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a605539.pdf


Report Date : 16 Feb 2014


Pagination or Media Count : 15


Abstract : We report on discovery of and strategies for designing new complex oxide materials in which two normally contradictory properties coexist, and its publication. In one example, switchable polar character (ferroelectricity) arising from non-centrosymmetric structure is achieved in a narrow-gap material through design and synthesis of cation and oxygen vacancy-driven tuning of band gap without loss of polar character. Shown for a single phase solid solution ferroelectric oxide perovskite (K,Ba),(Ni,Nb)O_(3-delta), this material exhibits a compositionally tunable and direct band gap in the range of 1.1 3.8 eV, with potential for novel nonlinear light-matter applications in addition to high-efficiency photovoltaic solar energy conversion. In a second example we report, with collaborators, on the discovery, synthesis and properties of a completely new family of non-perovskite complex oxide that exhibits ferroelectric and antiferromagnetic order. We report on publication of a new thin film synthesis strategy that enables, through epitaxial stabilization, low-energy and highly scalable growth of single-crystal heteroepitaxial complex oxide thin films featuring low-temperature deposition and a brief annealing under wellcontrolled conditions. Finally, we describe progress in using inelastic light scattering, in conjunction with other techniques, to characterize and quantify oxygen vacancy concentrations, including their effects on structure and electronic phase transitions.


Descriptors :   *BAND GAPS , *FERROELECTRICITY , *NARROW GAP SEMICONDUCTORS , *OXYGEN , ANNEALING , ANTIFERROMAGNETISM , ARCHITECTURE , CORES , DEPOSITION , ELECTRON TRANSITIONS , EPITAXIAL GROWTH , FERROELECTRIC MATERIALS , INELASTIC SCATTERING , LIGHT SCATTERING , NONLINEAR SYSTEMS , OXIDES , PARALLEL PROCESSING , PHASE TRANSFORMATIONS , PHOTOVOLTAIC EFFECT , POLAR REGIONS , SCALING FACTOR , SYNTHESIS , THIN FILMS , TUNING


Subject Categories : Electrical and Electronic Equipment
      Electricity and Magnetism
      Solid State Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE