**4. Conclusions**

The CuFe(2x)EuxO4 (where x = 0.00, 0.01, 0.02, 0.03) nanoparticles were synthesized by solution combustion method using mixture of fuels for the first time. XRD patterns reveal the polycrystalline spinel cubic structure having space group Fd3m with small amount of impurity phases at 38.87° and 48.96°. The SEM micrograph reveals the formation of dry foamy powders during combustion process and porous nature of the sample. The average grain size of the samples was measured from SEM micrographs. The chemical composition was analyzed by using EDS analysis. The dielectric parameters vary with frequency. In the copper ferrite, the role of the grains is very essential at greater frequency as compared to grain boundary's role. The radii of the semicircles decreased with increasing concentration; this sign indicates a decrease in relaxation. The humidity sensing response at higher concentration is very good as compared to other concentration. The response and recovery curve time was good as compared to other ferrite samples. The sample shows high stability at higher concentration with good sensing response for sensor applications. At lower concentration, europium-doped sample shows low sensing response; however, the low sensing responsible ferrites are used in battery and electronic applications.

**Author details**

, K. Manjunatha<sup>1</sup>

and Shidaling Matteppanavar<sup>7</sup>

, Vinayaka K. Pattar<sup>5</sup>

, V. Jagadeesha Angadi<sup>2</sup>

1 Department of Physics, School of Engineering, Presidency University, Bangalore,

3 Department of Physics, Research Centre, JNN College of Engineering, Shimoga,

4 Department of PG Studies and Research in Physics, Government Science College,

5 New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research,

6 Department of Physics, M.S. Ramaiah University of Applied Sciences, Bengaluru,

7 Department of Physics, Basavaprabhu Kore Arts, Science and Commerce College,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: jagadeeshbub@gmail.com

provided the original work is properly cited.

2 Department of Physics, P.C. Jabin Science College, Hubballi, India

*Enhanced Humidity Sensing Response in Eu3+-Doped Iron-Rich CuFe2O4…*

*DOI: http://dx.doi.org/10.5772/intechopen.90880*

, S.O. Manjunatha<sup>6</sup>

\*, B. Chethan<sup>3</sup>

,

I.C. Sathisha<sup>1</sup>

India

India

India

**87**

Y.T. Ravikiran<sup>4</sup>

Chitradurga, India

Bangalore, India

Chikodi, India

*Enhanced Humidity Sensing Response in Eu3+-Doped Iron-Rich CuFe2O4… DOI: http://dx.doi.org/10.5772/intechopen.90880*
