Effect of mixed alkali-element substitution on structural and magnetic properties of praseodymium manganites Pr0.9(Na1-xKx)0.1MnO3

TL;DR

This study investigates how substituting sodium and potassium at the A site in praseodymium manganites affects their structure and magnetism, revealing increased cell volume, reduced Jahn-Teller distortion, and canted ferromagnetic behavior.

Contribution

It provides new insights into how mixed alkali-element substitution influences structural and magnetic properties of praseodymium manganites, using detailed Rietveld analysis and magnetic characterization.

Findings

Cell volume increases with potassium content.

Jahn-Teller distortion decreases as x increases.

Magnetic behavior shows canted ferromagnetism and high Curie constants.

Abstract

The effect of cationic size mismatch at the A site at constant manganese valence on the structural and magnetic properties of a perovskite-type rare-earth manganate was investigated in the Pr0.9(Na1-xKx)0.1MnO3 solid solution system (0 <= x < 1). All members of this solid solution series are orthorhombic at room temperature, space group Pbnm. Structural refinements using the Rietveld method show that the cell volume increases and the static Jahn-Teller distortion decreases with increasing potassium content x. Magnetic properties are characterized by strong positive \theta p values, and are ascribed to a canted ferromagnetic arrangement. The high Curie constant values in the paramagnetic regime can be explained by a magnetic cluster model of 2-3 Mn ions.