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Formation Behavior and High Electrical Conductivity of Metastable Lithium Iron Silicate Crystals in Rapid Quenching of Li 2 O – Fe 2 O 3 – SiO 2 Melts
Author(s) -
Togashi Takuya,
Honma Tsuyoshi,
Komatsu Takayuki
Publication year - 2014
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.12701
Subject(s) - quenching (fluorescence) , spinel , materials science , metastability , analytical chemistry (journal) , electrical resistivity and conductivity , lithium (medication) , ferrimagnetism , activation energy , mineralogy , chemistry , metallurgy , magnetization , fluorescence , medicine , physics , organic chemistry , chromatography , quantum mechanics , endocrinology , magnetic field , electrical engineering , engineering
The formation behavior of spinel‐type LiFeSiO 4 crystals in the quenching of melts in the Li 2 O – Fe 2 O 3 – SiO 2 system was examined. It was found that high quenching rates of 10 3 ~ 10 6 K/min are favorable for the formation of LiFeSiO 4 crystals. The rapid quenched samples showed high electrical conductivities of the order of 10 −2 –10 −4 S/cm at room temperature and low activation energy for conduction of 0.1–0.2 eV. Both valences of Fe 2+ and Fe 3+ were present in the melt‐quenched samples, and rapid‐quenched samples showed ferrimagnetism. It is proposed that the chemical composition of LiFeSiO 4 formed in the rapid quenching of melts would be spinel‐type Li 1 + x Fe 3+ 1 − x Fe 2+ x SiO 4 . Because the Li 1 + x Fe 3+ 1 − x Fe 2+ x SiO 4 crystalline phases are metastable, the rapid quenching technique is necessary for their synthesis. The effects of quenching rate and composition on the formation of spinel‐type LiFeSiO 4 and on the electrical conductivity of quenched samples were discussed.