Room temperature magnetocaloric effect and refrigerant capacitance in La0.7Sr0.3MnO3 nanotube arrays

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Kumaresavanji, M (Author) Other; Sousa, CT (Author) REIT; Pires, A (Author) Other; pereira, a. m. (Author) FCUP; Lopes, AML (Author) Other; araujo, j. p. (Author) FCUP

Journal

Title: Applied Physics Letters

Vol. 105

Final page: 083110

ISSN: 0003-6951

Publisher: American Institute of Physics

Indexing

ISI Web of Knowledge - 32 Citations

Scopus - 31 Citations

Other information

Authenticus ID: P-009-VBB

DOI: 10.1063/1.4894175

Abstract (EN): High aspect ratio La0.7Sr0.3MnO3 nanotube (NT) arrays have been synthesized using nitrates based sol-gel precursor by nanoporous anodized aluminum oxide template assisted method. Their phase purity and microstructures were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive x-ray spectroscopy. Magnetocaloric effect (MCE) of as prepared NTs was investigated by means of field dependence magnetization measurements. Significant magnetic entropy change, -Delta S-M = 1.6 J/kg K, and the refrigerant capacitance, RC = 69 J/kg, were achieved near the transition temperature at 315K for 5 T. For comparison, a bulk sample was also prepared using the same precursor solution which gives a value of -Delta S-M = 4.2 J/kg K and a RC = 165 J/kg. Though the bulk sample exhibits higher Delta S-M value, the NTs present an expanded temperature dependence of -Delta S-M curves that spread over a broad temperature range and assured to be appropriate for active magnetic refrigeration. The diminutive MCE observed in manganite NTs is explained by the increased influence of surface sites of nanograins which affect the structural phase transition occurred by external magnetic field due to the coupling between magnetism and the lattice in manganese perovskites. Our report paves the way for further investigation in 1D manganite nanostructured materials towards applications in such magnetic refrigeration technology or even on hyperthermia/drug delivery. (C) 2014 AIP Publishing LLC.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5