X-ray diffraction and impedance spectroscopy measurements were performed to examine the effect of the substitution of calcium by potassium on the structure and dielectric properties in La_0.7Ca_0.3-xK_xMnO₃ compounds. Polycrystalline samples of La_0.7Ca_0.3-xK_xMnO₃ were prepared using solid state method. X-ray diffraction patterns show that these compounds exist at a single phase having a perovskite-like structure at room temperature. The X-ray data were analysed by the Rietveld method. For 0 £ x £ 0.075 the structure is orthorhombic. It becomes rhombohedral for x=0.1 and x=0.15. The impedance plane plots show semicircle arcs at different temperature and an electrical equivalent circuit has been proposed to explain the impedance results. A high frequency dielectric relaxation was also observed.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/17280 must be provided.

1. Microwave response of TCO coated glass analysed via transmission and reflectivity measurements
2. Structural properties and electrical behaviour in the polycrystalline lanthanum-deficient manganites La_1-x_xMnO₃