Impedance Spectroscopy Study of LaFe0.9Mn0.1O3 Material for Humidity Sensor Applications
Umairah1, Nayla Ramadhani1, Nova Nur Elisa Dewi2, Djoko Triyono2*, Iwan Sugihartono1**

1Program Studi Fisika, FMIPA, Universitas Negeri Jakarta, Rawamangun, Jakarta, 13220, Indonesia
2Departement of Physics, FMIPA, Universitas Indonesia, Depok, 16424, Indonesia

Abstract

This study examines the structural properties, elemental composition, and impedance response of LaFe0.9Mn0.1O3 material under varying relative humidity (RH) conditions for humidity sensor applications. The material was successfully synthesized using the sol-gel method. Structural characterization using X-ray Diffraction (XRD) confirmed that LaFe0.9Mn0.1O3 has an orthorhombic crystal structure with space group Pnma, in agreement with the Inorganic Crystal Structure Database (ICSD) No. 98-016-4083. Elemental composition analysis using X-ray Fluorescence (XRF) verified the presence of La, Fe, Mn, and O elements with weight percentages of 57.24%, 20.71%, and 2.26%, respectively, indicating good agreement with the expected stoichiometry. The electrical behaviour of the material was evaluated using electrochemical impedance spectroscopy (EIS) at different humidity levels, including low, ambient, and high RH conditions. The results show that the impedance response of LaFe0.9Mn0.1O3 changes significantly with variations in humidity, indicating good sensitivity to RH. Overall, the material exhibits a well-defined orthorhombic perovskite structure, appropriate elemental composition, and strong humidity-dependent electrical properties. These characteristics suggest that LaFe0.9Mn0.1O3 is a promising candidate for humidity sensor applications with good response and stability.

Keywords: LaFe0.9Mn0.1O3- Humidity sensor- Impedance spectroscopy- Perovskite oxide- Sol-gel synthesis.

Topic: Material Physics