Critical behaviour and magnetocaloric effect of nano crystalline La0.67Ca0.33Mn1-xFexO3 (x=0.05, 0.2) synthesized by nebulized spray pyrolysis
DSpace at IIT Bombay
View Archive InfoField | Value | |
Title |
Critical behaviour and magnetocaloric effect of nano crystalline La0.67Ca0.33Mn1-xFexO3 (x=0.05, 0.2) synthesized by nebulized spray pyrolysis
|
|
Creator |
NISHA, P
PILLAI, SS DARBANDI, A VARMA, MR SURESH, KG HAHN, H |
|
Subject |
Magnetic materials
Chemical synthesis Oxides Electron microscopy (STEM TEM and SEM) Critical phenomena Magnetic properties MAGNETIC-PROPERTIES COLOSSAL MAGNETORESISTANCE DOUBLE-EXCHANGE PARTICLES LA0.7CA0.3MNO3 MANGANITES TRANSPORT SYSTEMS SR SUPERPARAMAGNETISM |
|
Description |
The structure, critical exponents and magnetocaloric effect (MCE) of Nebulized Spray Pyrolysis (NSP) synthesized nano crystalline La0.67Ca0.33Mn1-xFexO3 (x = 0.05, 0.2) were investigated. The Reitveld refinement of XRD patterns show that the samples adopt an orthorhombic structure with Pnma space group. TEM inspection reveals that the average particle size is about 15 nm and 42 nm for NSP synthesized LCMFe0.05 and LCMFe0.2 samples respectively. The temperature and field dependent magnetization studies reveal the superparamagnetic state of La0.67Ca0.33Mn0.95Fe0.05O3 and spin-glass-like state of La0.67Ca0.33Mn0.8Fe0.2O3. The critical behaviour at the transition region studied using modified Arrott plot provides a second order nature of phase transition for both samples. The magnetocaloric studies show the maximum value of magnetic entropy change (Delta S-max) is in the range 2.3 J kg(-1) K-1 at 158 K for LCMFe0.05 and 0.3 J kg(-1) K at 92 K for LCMFe0.2 respectively at 5 T field. The field dependence of the magnetic entropy changes are also analysed, which show a power law dependence (Delta S-M infinity H-n, n = 0.72 (2)) at transition temperature, T-c = 162 K for LCMFe0.05 and n = 1.11(3) at 92 K for LCMFe0.2. (c) 2012 Elsevier B.V. All rights reserved.
|
|
Publisher |
ELSEVIER SCIENCE SA
|
|
Date |
2014-10-15T14:05:50Z
2014-10-15T14:05:50Z 2012 |
|
Type |
Article
|
|
Identifier |
MATERIALS CHEMISTRY AND PHYSICS, 136(1)66-74
http://dx.doi.org/10.1016/j.matchemphys.2012.06.029 http://dspace.library.iitb.ac.in/jspui/handle/100/15059 |
|
Language |
en
|
|