BARC/PUB/2019/0352

 
 

Near-room-temperature magnetocaloric effect in electron-doped manganite probed by local atomic structure and critical exponent theory

 
     
 
Author(s)

Shelke, A. R.; Shinde, K. P.; Patra, N.; Jha, S. N.; Bhattacharyya, D.; and others
(A&MPD)

Source

Journal of Magnetism and Magnetic Materials, 2019. Vol. 480: pp. 22-32

ABSTRACT

Near-room-temperature and enhanced magnetocaloric properties are investigated for the chemical combustion synthesized electron-doped manganite La1−xZrxMnO3 with x=0.05, 0.10 and 0.15. The single-phase rhombohedral crystal structure is observed particularly for the La0.90Zr0.10MnO3 (Zr10) system. Importantly, all the samples exhibit the paramagnetic-to- ferromagnetic (PM-to-FM) transition close to the room-temperature with the second-order phase transition. The analysis of the magnetic data in the critical region with different theoretical models such as 3D-Heisenberg, 3D-Ising, Mean-field, and Tri-critical mean-field suggested that the Zr10 sample exhibits the typical 3D-Heisenberg ferromagnetic characteristics. This indicated that the enhanced magnetic and magnetocaloric properties are governed by short-range exchange forces. Furthermore, the obtained data is also fitted with the Kouvel-Fisher method to obtain the transition-temperature, critical exponent β and it is found that the transition temperature and β values are totally consistent to that of the 3D-Heisenberg model. Significantly, the change in entropy |ΔSm| at 5 T is calculated to be 4.04 J·kg−1·K−1 at 304 K in case of Zr10 sample indicating that it can be one of the potential material for the future magnetic refrigeration technology working at near room-temperature.

 
 
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