Impact of silver addition on room temperature magneto-resistance in La0.7Ba0.3MnO3 (LBMO): Agx (x = 0.0, 0.1, 0.2, 0.3, 0.4)

TL;DR

This study investigates how adding silver to La0.7Ba0.3MnO3 enhances its magneto-resistance and physical properties, with optimal silver content achieving over 55% resistance change at room temperature.

Contribution

It demonstrates that silver addition improves grain morphology and significantly enhances magneto-resistance in La0.7Ba0.3MnO3, especially at specific compositions and sintering conditions.

Findings

Maximum MR of 55% at 300K with 0.3 Ag content

MR exceeds 60% at 270K for 0.4 Ag content

Silver improves grain morphology and physical properties

Abstract

La0.7Ba0.3MnO3 (LBMO):Agx (x = 0.0, 0.1, 0.2, 0.3, and 0.4) composites are synthesized by solid-state reaction route, the final sintering temperatures are varied from 1300 (LBMO1300Ag) to 1400 0C (LBMO1400Ag), and their physical properties are compared as a function of temperature and Ag content. All samples are crystallized in single phase accompanied by some distortion in main structural phase peaks at higher angles with increase in silver content. Though the lattice parameters (a, c) decrease, the b increases slightly with an increase in Ag content. The scanning electron micrographs (SEM) showed better grains morphology in terms of size and diffusion of grain boundaries with an increase in Ag content. In both LBMO1300Ag and LBMO1400Ag series the metal insulator transition (TMI) and accompanied paramagnetic-ferromagnetic transition (TC) temperatures are decreased with increase in Ag content. The sharpness of MI transition, defined by temperature coefficient of resistance (TCR), is improved for Ag added samples. At a particular content of Ag(0.3), the TMI and TC are tuned to 300K and maximum magneto-resistance at 7Tesla applied field (MR7T) of up to 55% is achieved at this temperature, which is more than double to that as observed for pure samples of the both 1300 and 1400 0C series at same temperature. The MR7T is further increased to above 60% for LBMOAg(0.4) samples, but is at 270K. The MR7T is measured at varying temperatures of 5, 100, 200, 300, and 400K in varying fields from +/- 7 Tesla, which exhibits U and V type shapes. Summarily, the addition of Ag in LBMO improves significantly the morphology of the grains and results in better physical properties of the parent manganite system.