Structural, electrical and microwave properties of (Sr_0.6Ca_0.4) (Co_yMn_1−y) O₃ (0.2 ≤ y ≤ 1.0) thick film ceramics

Abstract

Purpose – This paper aims to study the structural, electrical and microwave properties of (Sr0.6Ca0.4) (CoyMn1−y) O3 (0.2 ≤ y ≤ 1.0) thick-film ceramics. Design/methodology/approach – The thick films of (Sr0.6Ca0.4) (CoyMn1−y) O3 (0.2 ≤ y ≤ 1.0) on the alumina substrate have been delineated using screen printing technique. The structural analysis was carried out using an X-ray diffraction method and scanning electron microscopy. The direct current (DC) electrical resistivity is measured using a two-probe method. Microwave absorption was studied in the 8-18 GHz frequency range by using the Waveguide Reflectometer Method. The permittivity and permeability in the 8-18 GHz frequency range were measured by using Voltage Standing Wave Ratio slotted section method. Findings – The thick films have orthorhombic perovskite structure with dominant (020) plane. By using first-principle calculation method, theoretical and experimental lattice parameter and cell volume of (Sr0.6Ca0.4) (CoyMn1−y) O3 are matched with each other. The cobalt content changes the morphology from plates to needles. The DC electrical resistivity increases with increase in Co content and decreases with increase in temperature. (Sr0.6Ca0.4) (CoyMn1−y) O3 thick film shows 75 per cent microwave absorption both in the X band and Ku band. The microwave permittivity and permeability decreases with increase in frequency and Co content. Originality/value – Structural, electrical and microwave properties of (Sr0.6Ca0.4) (CoyMn1−y) O3 (0.2 ≤ y ≤ 1.0). Thick film ceramics on alumina substrate is reported for the first time.