@article { ISI:000230160700011, title = {Coprecipitation technique to prepare SrNb2O6}, journal = {Materials Characterization}, volume = {55}, number = {1}, year = {2005}, month = {JUL}, pages = {92-95}, publisher = {ELSEVIER SCIENCE INC}, type = {Article}, address = {360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA}, abstract = {

A mixture of ammonium oxalate and ammonium hydroxide was used to co-precipitate strontium and niobium ions as strontium oxalate and niobium hydroxide under basic conditions. This precursor yielded SrNb2O6 ceramics on calcining at 650 degrees C. This is a much lower temperature compared to preparation of SrNb2O6 by the traditional solid state method (900 degrees C). Transmission electron microscopy (TEM) revealed that the average particle size is 100 nm for the calcined powders. The room temperature dielectric constant at 1 kHz is found to be 550. The ferroelectric hysteresis loop parameters of these samples were also studied. (c) 2005 Elsevier Inc. All rights reserved.

}, keywords = {Ceramics, Electron microscopy, ferroelectric, Oxides, X-ray methods}, issn = {1044-5803}, doi = {10.1016/j.matchar.2005.04.002}, author = {Ravi, V} } @article {43878, title = {Mixed-stack charge transfer crystals of pillar[5]quinone and tetrathiafulvalene exhibiting ferroelectric features}, journal = {Chemistry- A European Journal }, volume = {23}, year = {2017}, month = {SEP}, chapter = {12630-12635}, abstract = {

Ferroelectric materials find extensive applications in the fabrication of compact memory devices and ultra-sensitive multifunctional detectors. Face-to-face alternate stacking of electron donors and acceptors effectuate long-range unidirectional ordering of charge-transfer (CT) dipoles, promising tunable ferroelectricity. Herein we report a new TTF-quinone system-an emerald green CT complex consisting pillar[5]quinone (P5Q) and tetrathiafulvalene (TTF). The CT crystals, as determined by single crystal synchrotron X-ray diffraction, adopt a 1:1 mixed-stack arrangement of donor and acceptor with alternating dimers of TTF and 1,4-dioxane encapsulated P5Q. The TTF-P5Q.dioxane crystal possesses a macroscopic polarization axis giving rise to ferroelectricity at room temperature. The CT complex manifests ferroelectric features such as optical polarization rotation, temperature-dependent phase transition and piezoelectric response in single crystals. Ferroelectric behavior observed in P5Q-based CT complex widens the scope for further work on this structurally intriguing and readily accessible cyclic pentaquinone.

}, keywords = {Acceptor, Charge-transfer complexes, Chemistry, Conductors, DDQ, Donor, ferroelectric, Macrocycles, Organic Metals, Pi-interaction, Pillar[5]quinone, salts, Transfer Complexes, Transport}, issn = {0947-6539}, doi = {10.1002/chem.201702577}, author = {Shivakumar, Kilingaru I. and Swathi, Kadaba and Goudappagouda and Das, Tamal C. and Kumar, Ashwani and Makde, Ravindra D. and Vanka, Kumar and Narayan, Kavassery S. and Babu, Sukumaran Santhosh and Sanjayan, Gangadhar J.} }