Preparation and properties of zirconium-doped copper calcium titanate ceramics for broadband electromagnetic spectrum conversion.

In this paper, zirconium-doped CaCu 3 Ti 4-x Zr x O 12 (0 ≤ x ≤ 0.3, CCTZO) ceramics were prepared by traditional solid-state reaction. The prepared CaCu 3 Ti 4-x Zr x O 12 display cubic phase structure, as shown by the XRD analysis, and interplanar spacing increase, as obtained by TEM. The surface morphologies, electrical conductivity, optical properties, solar and microwave thermal conversion characteristics of the synthesized samples were investigated in detail. The experimental results indicate that both the solar absorbance and thermal emittance of the samples could be tailored by Zr ions doping. In general, the CaCu 3 Ti 4-x Zr x O 12 system displays relatively high thermal radiation properties, with an optimal composition of CaCu 3 Ti 3.9 Zr 0.1 O 12 exhibiting a solar absorbance of 0.85 and a thermal emittance of 0.75. The incorporated Zr ions enhanced the solar–thermal conversion while weakened the microwave–thermal conversion. Under simulated solar irradiation (3 W/cm2), the equilibrium temperature of CaCu 3 Ti 3.9 Zr 0.1 O 12 could reach above 260 °C. The equilibrium temperature of CaCu 3 Ti 4 O 12 could reach up to 493 °C at a frequency of 2.45 GHz over 140 s. The results demonstrate that the CCTZO ceramics have the potential to emerge as the broadband electromagnetic wave–thermal conversion materials. [ABSTRACT FROM AUTHOR]