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Free keywords:
charge ordering, high pressure, iron oxides, transition metal oxide, Verwey transition, Bond strength (chemical), Metal insulator transition, Physicochemical properties, Transition metal oxides, Transition metals, Vanadium dioxide, Charge ordering, Charge ordering phenomena, Charge ordering transition, High pressure, Nanoelectronic devices, Near room temperature, Standard conditions, Verwey transitions, Iron oxides
Abstract:
Functional oxides whose physicochemical properties may be reversibly changed at standard conditions are potential candidates for the use in next-generation nanoelectronic devices. To date, vanadium dioxide (VO2) is the only known simple transition-metal oxide that demonstrates a near-room-temperature metal–insulator transition that may be used in such appliances. In this work, we synthesized and investigated the crystals of a novel mixed-valent iron oxide with an unconventional Fe5O6 stoichiometry. Near 275 K, Fe5O6 undergoes a Verwey-type charge-ordering transition that is concurrent with a dimerization in the iron chains and a following formation of new Fe−Fe chemical bonds. This unique feature highlights Fe5O6 as a promising candidate for the use in innovative applications. We established that the minimal Fe−Fe distance in the octahedral chains is a key parameter that determines the type and temperature of charge ordering. This model provides new insights into charge-ordering phenomena in transition-metal oxides in general. © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
