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Showing 1 to 17 of 17 for “"cation ordering"”.
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THE INTERPLAY BETWEEN CATION ORDERING AND ELASTICITY OF OMPHACITES TO UNRAVEL PTT PATHS OF METAMORPHIC ROCKS
… hosts. Natural omphacite crystals exhibit cationic ordering associated with crystallization temperature, which affects their elastic properties; the ordered configuration, characterised by space group P2/n, is indicative of lower temperature compared to the disordered configuration, with …
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Changes in the cation ordering of layered O3 Lix̳Ni₀.₅Mn₀.₅O₂ during electrochemical cycling to high voltages
… with a ... supercell that is characteristic of cation ordering in the transition metal layer. Furthermore, these superlattice reflections were found to have considerably weakened or completely disappeared in the charged samples. Comparing the 4.5 V and 5.3 V charged samples, fewer crystals in …
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Cell parameter systematics of the binary silicate olivines: methods for the determination of composition and intracrystalline cation ordering
… average radii, rM1 and rM2, of the octahedral cations in Fe-Mn, Ni-Fe, Mg-Mn, and Mg-, Fe-, and Mn-Ca binary olivines, using data from the literature. The resulting regression equations are given below. The coefficients of correlation exceed 0.997 in all cases. Fe-Mn binary olivines a= 3.527 + …
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Investigating the Thermal Stability and Cation Ordering in Layered Cathode LixMO2 (x ≤ 1; M = Co, Mn, Ni) Materials for Li-ion Rechargeable Batteries and Studying the Ferroelectric Properties of LiNbO3 Nanoparticles
… extensive attention because of their wide application in electronic, memory, battery, informatics, and optoelectronics devices. In this dissertation, we have studied two different types of oxide materials which are technologically important: LiMO 2 (M = Co, Mn, Ni), has served as cathode …
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Growth-Induced Cation Order and Magnetic Anisotropy Engineering in Iron Garnet Thin Films
… materials have long been studied for these applications, they have faced challenges in becoming adoptable technologies. However, with advanced research techniques and a deeper understanding of material behaviors, magnetic garnets are experiencing a renaissance. This thesis explores the …
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Stability of lithium aluminum manganese oxide cathodes for rechargeable lithium batteries
… from the ordered rocksalt to spinel type cation ordering results in an antiphase nanodomain structure, which becomes a ferroelastic domain structure during the cubic ---> tetragonal Jahn-Teller transformation, and thereby accommodates the transformation strains. (3) Al-doped spinels …
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Electrocaloric effects in multilayer capacitors of stoichiometric lead scandium tantalate with varying B‑site cation order
… bodies, and a summary of the effects of B‑site cation ordering on EC effects in PST. Basic heat flow dynamics and concomitant thermal boundary conditions are then summarised in the context of experimental techniques that can be employed for the evaluation of EC effects in bulk and MLC bodies. …
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Local Structures of Niobium-Containing Cation-Disordered Rocksalt Materials: Cobalt-Free Cathodes for Lithium-Ion Batteries
… world’s energy storage demands. Li-excess and cation-disordered materials have shown promise as materials with significantly higher capacities, supposedly achieved in part through reversible anionic redox, in addition to traditional transition metal redox. They also allow for a broad …
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Computational studies of cation and anion ordering in cubic yttria stabilized zirconia
The investigation of ordering and phase stability in the ZrO2-Y203 system involves two sets of calculations. The first set of calculations uses the cluster expansion method. A guide to the practical implementation of the cluster expansion outlines methods for defining a goal and choosing structures …
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Magneto-optical oxide thin films and integrated nonreciprocal photonic devices
… components in present day optical communication systems. Although highly desired by the fast development of silicon photonics, monolithically integrating such devices on a semiconductor platform has been challenging for decades both due to material incompatibility and device designs. In …
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Computational structure analysis of multicomponent oxides
… Carlo techniques are used to understand the cation ordering patterns of multicomponent oxides. Specifically, the lithium ion battery cation material LiNi0.5Mn0.5O2 and the thermoelectric material P2-NaxCoO2 (0.5 =/< x =/< 1) are investigated in the course of this research. It is found that at …
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The Cause of Anisotropy in Symmetrically Cubic Almandine and Spessartine Garnet
… of OH groups within the tetrahedral site, cation ordering of the dodecahedral and octahedral sites and strain leading to cubic symmetry violations. This thesis addresses previous hypotheses and suggests a new solution to the problem of anisotropy in almandine and spessartine garnet; the …
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Borate polyanion-based systems as Li- and Mg-ion cathode materials
… metal orthoborates form a solid solution, with cation order driven by the presence of directional d orbitals. Electrochemical studies show that Mg can be removed from the structure and replaced with Li in a 1:1 ion ratio. In the compound Mg2Mn(BO3)2 removal of 1 Mg is achieved giving a capacity …
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Development of first principles paramagnetic NMR methodologies to probe the complex local structural properties of Li-ion battery materials
… NMR spectra, helping to resolve the complex cation ordering as a function of Mn/Ti content in the series. For paramagnetic centres with an unquenched orbital component of the electron magnetic moment(s), the spin-orbit coupling effects also contribute to the paramagnetic NMR shift and shift …
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Magnesium-manganese solid solution in the olivine and humite groups
… least-squares techniques to investigate cation ordering. Forsterite from Langban, Sweden [(Mg₀.₅₁₉Mn₀.₄₈₂Ca₀.₀₀₃Fe₀.₀₀₁)₂SiO₄, Pbnm, a = 4.94(2) b = 10.419(4), c = 6.123(2)A] was refined to R=0.029 (R<sub>W</sub>=0.028) using 731 unique structures factors with F<sub>obs</sub> > …
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The Chemistry and Crystallography of Doped Bixbyite, Braunite and Novel Anion-Deficient Fluorite Oxides
… for at least the last decade for their application as semiconductors, optoelectronics, superconductivity, magnetism, and catalysis. The bixbyite structure has deep historical roots within solid-state chemistry and crystallography, the first correct crystal structure was solved by Linus …