Study on the phase separation of La0.7Sr0.3MnO3 nanoparticles by electron magnetic resonance

Abstract In this work, the technique of electron magnetic resonance (EMR) is used to measure the magnetic resonant spectra of La 0.7 Sr 0.3 MnO 3 nanoparticles synthesized by sol–gel routes with three different gelation agents (S1: Urea+citric acid; S2: citric acid, and S3: Urea+tri-sodium citrate). The purpose of this study is to investigate the influence of synthesis conditions on the magnetic properties of nanoparticles. Our ESR results show that Curie temperatures of La 0.7 Sr 0.3 MnO 3 nanoparticles with different gelation agents are slightly different ( T c ∼340 to 360 K) and possess both paramagnetic (PM) and ferromagnetic (FM) phases in the temperature below T c . Besides, a sharp FM–PM transition indicates that the combined agent of Urea+tri-sodium citrate creates a better quality in CMR nanomagnets.