Nisha, P. ; Savitha Pillai, S. ; Darbandi, Azad ; Varma, Manoj Raama ; Suresh, K. G. ; Hahn, Horst (2012)
Critical behaviour and magnetocaloric effect of nano crystalline La0.67Ca0.33Mn1−xFexO3 (x = 0.05, 0.2) synthesized by nebulized spray pyrolysis.
In: Materials Chemistry and Physics, 136 (1)
doi: 10.1016/j.matchemphys.2012.06.029
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
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 (ΔSmax) 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 (ΔSM ∞ Hn, n = 0.72 (2)) at transition temperature, TC = 162 K for LCMFe0.05 and n = 1.11(3) at 92 K for LCMFe0.2.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2012 |
| Autor(en): | Nisha, P. ; Savitha Pillai, S. ; Darbandi, Azad ; Varma, Manoj Raama ; Suresh, K. G. ; Hahn, Horst |
| Art des Eintrags: | Bibliographie |
| Titel: | Critical behaviour and magnetocaloric effect of nano crystalline La0.67Ca0.33Mn1−xFexO3 (x = 0.05, 0.2) synthesized by nebulized spray pyrolysis |
| Sprache: | Englisch |
| Publikationsjahr: | 14 September 2012 |
| Verlag: | Elsevier Science Publishing |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Materials Chemistry and Physics |
| Jahrgang/Volume einer Zeitschrift: | 136 |
| (Heft-)Nummer: | 1 |
| DOI: | 10.1016/j.matchemphys.2012.06.029 |
| Kurzbeschreibung (Abstract): | 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 (ΔSmax) 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 (ΔSM ∞ Hn, n = 0.72 (2)) at transition temperature, TC = 162 K for LCMFe0.05 and n = 1.11(3) at 92 K for LCMFe0.2. |
| Freie Schlagworte: | Magnetic materials, Chemical synthesis, Oxides, Electron microscopy (STEM, TEM and SEM), Critical phenomena, Magnetic properties |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Gemeinschaftslabor Nanomaterialien 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften |
| Hinterlegungsdatum: | 17 Jun 2014 11:11 |
| Letzte Änderung: | 17 Jun 2014 11:11 |
| PPN: | |
| Sponsoren: | Dr. Manoj Raama Varma would like to thank German Academic Exchange Service DAAD for the support to his visit INT, Karlsrhue., Nisha and Dr. Manoj Raama Varma would like to thank Department of Science and Technology, Government of India for Providing HRTEM facility at NIIST, Trivandrum Defence Research Development Organization, Government of India for supporting the project. |
| Export: | |
| Suche nach Titel in: | TUfind oder in Google |
 |
Frage zum Eintrag |
Optionen (nur für Redakteure)
 |
Redaktionelle Details anzeigen |
Drucken
Impressum