Enhanced Magnetocaloric Effect Driven by Interfacial Magnetic Coupling in Self-Assembled Mn3O4–La0.7Sr0.3MnO3 Nanocomposites.

Vandrangi, Suresh K.; Yang, Jan-Chi; Zhu, Yuan-Min; Chin, Yi-Ying; Lin, Hong-Ji; Chen, Chien-Te; Zhan, Qian; He, Qing; Chen, Yi-Chun; Chu, Ying-Hao

Abstract

Magnetic refrigeration, resulting from the magnetocaloric effect of a material around the magnetic phase-transition temperature, is a topic of great interest as it is considered to be an alternate energy solution to conventional vapor-compression refrigeration. The viability of a magnetic refrigeration system for magnetic cooling can be tested by exploiting materials in various forms, from bulk to nanostrucutres. In this study, magnetocaloric properties of self-assembled Mn3O4–La0.7Sr0.3MnO3 nanocomposites, with varying doping concentrations of Mn3O4 in the form of nanocrystals embedded in the La0.7Sr0.3MnO3 matrix, are investigated. The temperatures corresponding to the paramagnetic-to-ferromagnetic transitions are higher, and the values of change in magnetic entropy under a magnetic field of 2 T show an enhancement (highest being ∼130%) for the nanocomposites with low doping concentrations of Mn3O4, compared to that of pure La0.7Sr0.3MnO3 thin films. Relative cooling power remain close to those of La0.7Sr0.3MnO3. The enhanced magnetic phase-transition temperature and magnetocaloric effect are interpreted and evidenced in the framework of interfacial coupling between Mn3O4 and La0.7Sr0.3MnO3. This work demonstrates the potentiality of self-assembled nanostructures for magnetic cooling near room temperature under low magnetic fields.

• Journal Article Type: Article
• Acceptance Date: Nov 17, 2015
• Online Publication Date: Nov 17, 2015
• Publication Date: 2015-11
• Deposit Date: Dec 5, 2016
• Journal: ACS Applied Materials and Interfaces
• Print ISSN: 1944-8244
• Electronic ISSN: 1944-8252
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 7
• Issue: 48
• Pages: 26504-26511
• DOI: https://doi.org/10.1021/acsami.5b07585
• Public URL: https://durham-repository.worktribe.com/output/1390839