Investigation on the Optical, Electrical and Dielectric Properties of La_0.7Ca_0.3MnO₃ (LCMO) <i>Via.</i> Different Routes: A Comparative Analysis of Micro and Nanoparticles

Abstract

In the proceeding way of material research in the field of manganites, LCMO micro and nanoparticles are synthesized via. the solid-state reaction route, glycine-nitrate combustion method respectively. The phase confirmation is done by XRD, FT-IR technique and the surface morphology viewed by Scanning Electron Microscope (SEM). The energy band gap obtained from Diffuse Reflectance Spectroscopy clearly suggests that the band gap of nanoparticles (2.06eV) is larger than that of the microparticles (1.58eV). Both samples comprise of wide band-gap semiconductor, so the refractive index is calculated using Herve and Vandamme relation. The impedance spectroscopy and dielectric properties of the two samples are studied from room temperature to 100oC over the frequency range 102-106 Hz. The Cole-Cole plot of impedance is fitted using the RC-Circuit R(QgRg)(QgbRgb)(CRin). The dielectric property is found to be enhanced in nanoparticles as compared to the microparticles. The findings suggest the nanoparticles be promising candidates in the field of high frequency devices as compared to micro.

Structural and critical properties of Pr0.5Sr0.5MnO3 nanoparticle

“…According to recent studies, the grain size or crystalline size is a very important factor, which strongly influences the physical properties of materials. The influence of size effect on the structure, electrical and magnetic properties of manganites synthesised by different methods has been extensively studied [13][14][15][16][17][18], but there are still controversial issues related to the nature of magnetic interactions and the critical behaviour in manganites (namely PSMO [19,20]) that need to be resolved. In this work, we give some results and discussions on the structure and the critical behaviour of a Pr 0.5 Sr 0.5 MnO 3 nanoparticle (PSMO-NP) sample with an average crystalline size of <D> = 58 ± 2 nm fabricated by a combination of reactive milling and heat treatment methods, a simple method can be applied to fabricate nanoparticle manganites.…”

Electrical and magnetic properties of La0.7Ca0.3MnO3 nanoparticle prepared by reactive milling method

“…It is also known that the particle or crystal size is an important factor, which strongly influences the physical properties of material. The effects of the particle/crystal size on the structural, electrical and magnetic properties of LCMO nanoparticles (NPs) synthesised by various techniques (such as sol-gel [15,16], mechanical milling [13,17,18] and other chemical methods [19][20][21][22]) have thus been widely investigated. In manganites, the intrinsic MR effect taking place around T C with a very large MR int value (called colossal magnetoresistance: CMR) is usually observed on bulk samples, whereas it is quite small or disappears in NPs [10,11,23].…”