T-ZnOw/FCIPs with vertical-orientated structure achieving temperature-stable broadband microwave absorption.

[Display omitted] • T-ZnO w can enable FCIPs to show the vertically oriented distribution. • The vertical distribution can significantly improve impedance matching. • The effective bandwidth of T-ZnO w /FCIPs covers the entire X-band over 30–350 °C. Currently, most magnetic high-temperature microwave absorbing materials (MAMs) suffer from the problem of impedance mismatch caused by sudden increase in conductivity along with the changing temperature. Herein, the tetra-needle zinc oxide whisker (T-ZnO w) is used as a structural template to manage the spatial distribution of flake carbonyl iron powders (FCIPs), achieving temperature-stable broadband microwave absorption in the range of 30–350 °C. By adjusting the filling content of T-ZnO w makes FCIPs change from random distribution to a vertically oriented distribution. This distribution provides more stable conductive paths and facilitates low temperature-sensitivity conductance loss. At the same time it provides more transmission channels for the incidence of electromagnetic waves (EMW) and achieves excellent impedance matching. Compatibility of conductance loss and impedance matching is thus achieved. The effective absorption bandwidth (reflection loss (RL) < −10 dB) of T-ZnO w /FCIPs in the range of 30–350 °C could cover entire X-band (8.2–12.4 GHz). This work proposes a simple method to adjust the spatial distribution of absorbers and provides a valuable inspiration for the preparation of temperature-stable broadband MAMs. [ABSTRACT FROM AUTHOR]