Manganaro Nicholas S, Ambos Scott D, DeCapua Matthew, Thiel Scott D, Mitchell Wyatt E, Liu Zhenxian, Zhang Dongzhou, Nguyen Phuong Q H, Lavina Barbara, Alp Esen Ercan, Yan Jun, Walsh James P S
Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
Inorg Chem. 2024 May 27;63(21):9763-9770. doi: 10.1021/acs.inorgchem.3c04631. Epub 2024 May 13.
The delafossites are a class of layered metal oxides that are notable for being able to exhibit optical transparency alongside an in-plane electrical conductivity, making them promising platforms for the development of transparent conductive oxides. Pressure-induced polymorphism offers a direct method for altering the electrical and optical properties in this class, and although the copper delafossites have been studied extensively under pressure, the silver delafossites remain only partially studied. We report two new high-pressure polymorphs of silver ferrite delafossite, AgFeO, that are stabilized above ∼6 and ∼14 GPa. In situ X-ray diffraction and vibrational spectroscopy measurements are used to examine the structural changes across the two phase transitions. The high-pressure structure between 6 and 14 GPa is assigned as a monoclinic 2/ structure that is analogous to the high-pressure phase reported for AgGaO. Nuclear resonant forward scattering reveals no change in the spin state or valence state at the Fe site up to 15.3(5) GPa.
铜铁矿是一类层状金属氧化物，因其能够在具有面内电导率的同时展现出光学透明性而备受关注，这使得它们成为开发透明导电氧化物的有前景的平台。压力诱导多晶型为改变这类材料的电学和光学性质提供了一种直接方法，尽管铜铁矿在压力下已得到广泛研究，但银铁矿的研究仍不充分。我们报道了两种新的高压多晶型银铁氧体铜铁矿AgFeO，它们在约6 GPa和约14 GPa以上压力下稳定存在。利用原位X射线衍射和振动光谱测量来研究两个相变过程中的结构变化。6至14 GPa之间的高压结构被确定为单斜2/结构，类似于报道的AgGaO高压相。核共振正向散射表明，在高达15.3(5) GPa的压力下，Fe位点的自旋态和价态没有变化。
