JURNAL SAINS MATERI INDONESIA (JUSAMI) ISSN: 1411-1098 (print), 2614-087X (online) VOL. 23, ISSUE 1, October 2021 DOI: https://doi.org/10.17146/jsmi.2021.23.1.6303 *CORRESPONDING AUTHOR | Y. E. Gunanto |  yohanes.gunanto@uph.edu 9 ORIGINAL ARTICLE The Structural, Impedance and Dielectric A Ferrite Core of Iron Manganite and Its Composite Y. E. Gunanto 1,* , H. Sitompul 1 , M. P. Izaak 1 and W. A. Adi 2 1 Dept. of Physics of Edu., Faculty of Education, Universitas Pelita Harapan, Karawaci, Tangerang 15811, Indonesia 2 Research and Technology Center for Nuclear Advanced Materials, National Research and Innovation Agency, Indonesia ABSTRACT – Samples with single-phase MnFeO3 and multiphase MnFeO3/ZnFe2O4 (30/70), and MnFeO3/ZnFe2O4/LaMnO3 (30/40/30) have been successfully prepared as ferrite cores by the solid- state reaction method using high energy milling. Crystal structure, surface morphology, impedance, AC-conductivity and dielectric quantities, such as dielectric constant and dielectric loss have been studied. The crystalline structures for MnFeO3, ZnFe2O4, and LaMnO3 are hexagonal, cubic and monoclinic, The Rietveld program used for XRD analysis resulted in the composition fractions of single phase MnFeO3, multiphase MnFeO3/ZnFe2O4 (31/69), and MnFeO3/ZnFe2O4/LaMnO3 (31/40/29). The morphology of all samples has a heterogeneous shape and size with low porosity. The single-phase impedance of MnFeO3 is higher than the multiphase sample. The conductivity of the three samples has the same pattern, which is relatively constant at low frequencies and begins to increase at frequencies above 10 kHz. The dielectric constant and dielectric loss (tan ) have high values at low frequencies, decrease exponentially with increasing frequency and are relatively fixed at high frequencies. ARTICLE HISTORY Received: 12 May 2021 Revised: 6 October 2021 Accepted: 13 October 2021 KEYWORDS Ferrite core, Milling, Single-multiphase, Dielectric constant, Loss tangent INTRODUCTION Ferrite is a ceramic compound of transition metals with oxygen, which is ferrimagnetic but not conductive. The ferrite used in transformer or electromagnetic cores contains iron oxide combined with manganese [1-4], zinc, and / or nickel compounds [5-8]. These materials have high resistivity or low electrical conductivity which prevents eddy currents in the core from causing energy loss. Iron manganite (MnFeO3) has its impedance and dielectric constant which decreases with increasing frequency [1, 4]. The electrical resistivity of nickel zinc nano ferrites is highly dependent on the size of the crystallinity and with increasing frequency, the dielectric constant decreases [5, 6], and the value of tan  also decreases [7, 8]. The perovskite LaMnO3 compound, with increasing frequency will also experience a decrease in impedance, dielectric and tan  constants [9], and also their electrical conductivity [10]. Several methods have been used for the sample preparation process, for example solid reaction [1, 10], sono-chemical [2], sol-gel auto-combustion [4, 6], coprecipitation [5], the polymerizable complex [9]. Of the several methods, the solid reaction is the easiest and cheapest method. This paper will discuss the structure, surface morphology, impedance, dielectric constant and loss tangent (tan) of single phase MnFeO3, two phases MnFeO3/ZnFe2O4 (30/70), and three phases MnFeO3/ZnFe2O4/LaMnO3 (30/40/30). All samples were processed using the solid reaction method by milling in a wet state for 10 hours. EXPERIMENTAL METHOD Materials and Instruments Each sample is made with the following reaction in Equation 1 to 3.  2  3 +  2  3 → 2  3 (1)  +  2  3 →  2  3 (2)  2  3 + 2  2 → 2  3 (3) To identify the phases formed, the composition, crystal structure and lattice parameters used a Philips PW1710 X-ray diffractometer (XRD),  −  radiation (λ = 1.5406 Å). Surface morphology was characterized using the scanning electron microscopy (SEM) type JEOL (JED-2300). While the LCR meter, type HIOKI-5020 is used for measuring impedance, electrical conductivity, dielectric constant and loss tangent ( tan ) in a frequency of 1-10 5 Hz.