Characterization of grain boundary conductivity of spin-sprayed ferrites using scanning microwave microscope

Myers, J.; Nicodemus, T.; Zhuang, Yan; Watanabe, Tomoaki; Matsushita, Nobuhiro; Yamaguchi, Masahiro

doi:10.1063/1.4860941

Cited by 6 publications

(2 citation statements)

References 16 publications

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“…Another approach to understand the difference of electrical conductivity between the thin films and single crystals are the grain boundaries, which exists in the thin films in contrast to the single crystalline reference samples. Reports in literature on Fe 3 O 4 films have shown that the grain boundaries are better electrical conductors than the bulk grains [31,32]. As the crystal structures of both Fe 1−x O and Fe 3 O 4 are similar, one may deduce a similarly better conductivity in grain boundaries for Fe 1−x O films compared to bulk.…”

Section: Electrical Resistivitymentioning

confidence: 92%

Phase formation and electrical properties of reactively sputtered Fe_1−xO thin films

Evertz,

Nicolin,

Cheng

et al. 2023

J. Phys. D: Appl. Phys.

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Wüstite, Fe1−x O, is a crucial phase for the transition to CO2-free steel manufacturing as well as promising for electrochemical applications such as water splitting and ammonia synthesis. To study the effect of interfaces in these applications, thin-film model systems with defined interfaces are ideal. Previous studies lack a description of the growth mechanism to obtain Fe1−x O thin films. Here, we investigate the phase formation of metastable Fe1−x O during reactive magnetron sputtering while systematically varying the O2/Ar flow ratio from 1.8% to 7.2% and the pressure–distance product between 3.5 and 7.2 Pa cm. If bulk diffusion is minimized, thin films containing 96 vol.% wüstite and 4 vol.% Fe as impurity phase were achieved. Therefore, the wüstite phase formation appears to be surface diffusion dominated. To reveal the influence of impurity phases in wüstite on the electrical resistivity, systematic electrical resistivity measurements while cooling in situ were performed for the first time. The electrical resistivity was lower than that of single crystals of the respective iron oxides. This is attributed to the formation of Fe-rich layers at the substrate-film interface, which serve as additional conduction paths.

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Section: Electrical Resistivitymentioning

confidence: 92%

Phase formation and electrical properties of reactively sputtered Fe_1−xO thin films

Evertz,

Nicolin,

Cheng

et al. 2023

J. Phys. D: Appl. Phys.

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show abstract

“…According to the Kramers–Kronig relations, the material responses (such as absorbance and reflectance) to electromagnetic waves are related to the phase and amplitude of the output signal at different frequencies. , The phase and amplitude of in-phase and out-of-phase microwave signals can reflect the imaginary part (capacitance, MIM-C) and real part (resistance, MIM-R) of the tip–sample impedance . These signals describe the electron characteristics in different microregions: − (1) weaker MIM-C values with a stronger capacitance and (2) stronger MIM-R values with a stronger reflected wave strength. For metals, both features correspond to a higher conductivity and a higher electron concentration. − …”

mentioning

confidence: 99%

Characterizing Local Electronic States of Twin Boundaries in Copper

Ni,

Cao,

Zhong

et al. 2024

Nano Lett.

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Grain boundaries (GBs) and twin boundaries (TBs) in copper (Cu) are two major planar defects that influence electrical conductivity due to their complex electron transport characteristics, involving electron scattering and electron concentration. Understanding their local electronic states is crucial for the design of future conductor materials. In this study, we characterized electron behaviors at TBs and GBs within one Cu grain using atomic force microscopy. Our findings revealed that, compared with GBs, TBs exhibit better current transport capability (direct-current mode) and larger electromagnetic loss (high-frequency microwave mode). Both kelvin probe force microscopy and theoretical analysis suggested that TBs with smaller lattice disorder possess lower density of states at the Fermi level. The reduced density of states may result in decreased electron scattering and a lower electron concentration at TBs. The latter can be highlighted by the high-frequency skinning effect, manifested as larger electromagnetic loss and weaker high-frequency conductivity.

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SMM studies on high-frequency electrical properties of nanostructured materials

Zhuang¹,

Myers²,

Ji³

et al. 2023

Modeling, Characterization, and Production of Nanomaterials

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Characterization of grain boundary conductivity of spin-sprayed ferrites using scanning microwave microscope

Cited by 6 publications

References 16 publications

Phase formation and electrical properties of reactively sputtered Fe_1−xO thin films

Phase formation and electrical properties of reactively sputtered Fe_1−xO thin films

Characterizing Local Electronic States of Twin Boundaries in Copper

SMM studies on high-frequency electrical properties of nanostructured materials

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Characterization of grain boundary conductivity of spin-sprayed ferrites using scanning microwave microscope

Cited by 6 publications

References 16 publications

Phase formation and electrical properties of reactively sputtered Fe1−x O thin films

Phase formation and electrical properties of reactively sputtered Fe1−x O thin films

Characterizing Local Electronic States of Twin Boundaries in Copper

SMM studies on high-frequency electrical properties of nanostructured materials

Contact Info

Product

Resources

About

Phase formation and electrical properties of reactively sputtered Fe_1−xO thin films

Phase formation and electrical properties of reactively sputtered Fe_1−xO thin films