CeO₂ Nanorods and Nanocubes: Impact of Nanoparticle Shape on Dilatometry and Electrical Properties

Abstract

The electrical and dilatometric properties of CeO 2 nanopowders were examined as function of particle shape and size, including nanorods and nanocubes. Nanorods show continuous irreversible shrinkage, linked to particle reordering and compaction. Thermal expansion of CeO 2 nanocubes was analyzed and was found to be consistent with literature data for microcrystalline ceria with no apparent nanosize effects. The electrical properties of the loosely compacted nanopowders were generally found to be characterized by n-type electronic conduction, except for proton conductivity contributions associated with adsorbed moisture at temperatures below 400°C. The P O2 and temperature dependences of the conductivity were examined in terms of defect chemical models. The lower effective enthalpy of reduction for nanorods (1.5 eV) in comparison with nanocubes (1.8 eV), both being much smaller than the value found for "bulk" ceria (4.7 eV), can be related to the larger surface to volume ratio of the nanorods, where oxide ion removal is more facile and less energy costly.

Role of anisotropy in determining stability of electrodeposition at solid-solid interfaces

“…Controlling the growth of dendrites during electrodeposition at a solid electrolyte-metal interface could enable the use of metal anodes, especially Li 14 , on which several high energy density batteries like Li-O 2 and Li-S rely [15][16][17] . Solid electrolyte systems also offer the advantages of improved safety, absence of leakage, better chemical and mechanical stability, and possibility of miniaturisation through thin film processing techniques for integration in devices like laptops and cellphones 18,19 .…”

Fluoride‐ion‐conducting Polymers: Ionic Conductivity and Fluoride Ion Diffusion Coefficient in Quaternized Polysulfones

“…All NMR experiments were performed on an AVANCE-III-HD 400 NMR spectrometer manufactured by Bruker Biospin and operating at 400 MHz and 376 MHz for the 1 Ha nd 19 FL armor frequency,r espectively.Acommercial high-resolution magic angle spinning (HRMAS) triple-resonance 4mmp robe head from DOTY Scientific was used, which was equipped with a 2 Hl ock channel and am agnetic field gradient coil aligned along the magic-angle spinning axis. With respect to instrumental setups used in liquid-state NMR, for which typical sample volumes are of the order of % 500 mL, the HRMAS probe head allows much smaller sample volumes ( % 20 mL) to be used, which translates into an et increase in sensitivity for mass-limited samples.…”

“…[1,2] Other well-known high temperature inorganicF À conductors are CaF 2 ,B aF 2 and LaF 3 . [3][4][5] However,t he ionic conductivity of these ceramic solids is well below 0.1 mS cm À1 at around 300 K. [3] The best inorganic fluoridei on conductor at room temperature is PbSnF 4 with ac onductivity of around 1mScm À1 .…”

“…Historically,s olid fluoride ion conductors were among the first describedi nl iterature:a lready in 1838 Faraday discovered lead fluoridea sas olid with predominant fluoride ion conductivity. [1,2] Other well-known high temperature inorganicF À conductors are CaF 2 ,B aF 2 and LaF 3 . [3][4][5] However,t he ionic conductivity of these ceramic solids is well below 0.1 mS cm À1 at around 300 K. [3] The best inorganic fluoridei on conductor at room temperature is PbSnF 4 with ac onductivity of around 1mScm À1 .…”

Electrical and Mechanical Properties of Zirconia Based Cubic/Tetragonal Composite Electrolytes Prepared by Solution Coating Method

“…Solid state ionics is a new branch of material science and engineering which deals with preparation, characterization and application of ionic solid electrolytes which have high ionic conductivity [1]. This field of materials science was developed during the late of 1960s, after first report of high ionic conductivity in solids like Na-b alumina [1]. Composite materials which are heterogeneous mixture of solid phases, have introduced a new degree of freedom in the search for advanced functional materials [2].…”