Thin and temperature-resistant TiO₂–Sr_1−xLa_xTiO₃ (x = 0.1–0.3) composite ceramics for microwave absorption in the X-band

Abstract

Recently, high-temperature stability is a challenge in a number of microwave absorption materials. Hence, researchers are still searching for a novel material system preferably with a high-temperature resistance to be applied in the field of microwave absorption. Here, in the current study, toward this aim, lanthanum (La)-doped strontium titanate (SrTiO₃) blended with TiO₂ were fabricated by hot-press sintering in a vacuum. The as-prepared samples are denoted as TiO₂–Sr_1−xLa_xTiO₃ with x varying from 0.1 to 0.3 in steps of 0.1. Scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), and microwave vector network analyzer were carried out to study their morphology, phase composition, structure, and electromagnetic and microwave absorption properties, respectively. It is revealed that the La atom was efficiently doped at the Sr-site in SrTiO₃. Benefiting from the tunability of its dielectric and impedance properties, TiO₂–Sr_1−xLa_xTiO₃ can be utilized in a highly efficient way to absorb microwave radiations with a decent design. Results illustrated that TiO₂–Sr_1−xLa_xTiO₃ (x = 0.2) with a thickness of only 0.42 mm exhibits a high microwave absorption efficiency of −40.89 dB and can achieve a 2.82 GHz bandwidth of reflection loss value below −5 dB. Thus, TiO₂–Sr_1−xLa_xTiO₃ composites ceramics can be served as an opening opportunity for the application of high-temperature stability and tunable high-performance effectiveness microwave absorption materials in stealth technology and information security.