Inter comparison of the magneto transport of La2/3Ca1/3MnO3: Ag/In polycrystalline composites

TL;DR

This study compares the magneto-transport properties of La2/3Ca1/3MnO3 composites doped with Ag and In, revealing enhanced TCR and MR with Ag doping and deterioration with In, linked to grain morphology changes.

Contribution

It provides a comparative analysis of Ag and In doping effects on magneto-transport in La2/3Ca1/3MnO3, highlighting the role of grain morphology in these properties.

Findings

Ag doping increases TCR and TFM, with highest TCR of 15% near TFM.

In doping decreases TFM and TCR, with inferior grain morphology.

Ag-doped samples show improved magneto-transport properties compared to pristine and In-doped samples.

Abstract

In this article, we report the synthesis, magneto transport features, and magnetization of polycrystalline La2/3Ca1/3MnO3:Agx/Inx composites with x = 0, 0.1, 0.2, 0.3 and 0.4. In case of Ag the temperature coefficient of resistance (TCR) near ferromagnetic (FM) transition enhances significantly with addition of Ag. The FM transition temperature (TFM) is also increased slightly with Ag doping. Magneto-transport measurements revealed that magneto-resistance (MR) is found to be maximum near TFM. Very sharp TCR is seen near TFM with highest value of up to 15 % for Ag (0.4) sample, which is an order of magnitude higher than as for pristine sample and is the best value yet reported for any polycrystalline LCMO compound. Increased TCR, TFM and significant above room temperature MR of La2/3Ca1/3MnO3:Agx composites is explained on the basis of improved grains size. Interestingly the La2/3Ca1/3MnO3:Inx composites behaved exactly in opposite way resulting in decreased TFM, and TCR compared to pristine LCMO compound. In fact the grains morphology of LCMO:Inx composites is seen inferior to pristine LCMO which is opposite to the LCMO:Agx case.