Microwave properties of composite Ba_0.5Sr_0.5Fe_11.7Mn_0.15Ti_0.15O₁₉/La_0.7Ba_0.3MnO₃ material

Mn-Ti substituted Barium - Strontium Hexaferrite and Barium - Lanthanum Manganite both well established materials which have been shown poses microwave absorbtion properties. As the properties of composite system are a composition sensitive, composite materials must be properly designed to meet a specific application. In this paper, we report our recent investigation on microwave absorbtion properties of composite Ba_0.5Sr_0.5Fe_11.7Mn_0.15Ti_0.15O₁₉/La_0.7Ba_0.3MnO₃ system. Composite components respectively Ba_0.5Sr_0.5Fe_11.7Mn_0.15Ti_0.15O₁₉ and La_0.7Ba_0.3MnO₃were prepared through mechanical alloying route employing a planetary ball mill for 20 hrs. The two milled powders were sintered at a temperature 1100 0C for 10 hours to ensure the crystallization towards fully crystalline materials. Composites with 2 different compositions were studied by FTIR and VNA from which results were compared with that of each component. Results of the investigation concluded that, the composite of Ba_0.5Sr_0.5Fe_11.7Mn_0.15Ti_0.15O₁₉/La_0.7Ba_0.3MnO₃ system is a good microwave absorbing material in the frequency range 9 GHz-15 GHz, particularly, sample with coded A03B07 has a wide range frequencies absorption.