Enhanced magnetocaloric properties of La0.8K0.2-xPbxMnO3 nanoparticles by optimizing Pb doping concentrations. Issue 12 (15th June 2022)

• Record Type: Journal Article
• Authors: Ait Bouzid, Sara; Essoumhi, Abdellatif; Rostas, Arpad Mihai; Kuncser, Andrei Cristian; Negrila, Constantin Catalin; Iacob, Nicusor; Galatanu, Andrei; Popescu, Bogdan; Sajieddine, Mohammed; Galca, Aurelian Catalin; Kuncser, Victor
• Is Part Of: Ceramics international. Volume 48:Issue 12(2022)
• Page Start: 16845
• Page End: 16860
• Publication Date: 2022-06-15
• Subjects: Magnetocaloric effect -- Magnetic entropy change -- EPR -- Perovskite; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.02.239
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Polycrystalline La0.8 K0.2- x Pb x MnO3 ( x = 0.05, 0.10, 0.15, 0.20) ceramics were successfully prepared by flash combustion route and their structural, morphological, magnetic and magnetocaloric properties were investigated. Structural analyses using X-ray diffraction reveal that all samples are crystallized in the rhombohedral structure and belong to R 3 ‾ c space group. The increase of Pb doping does not modify the crystalline structure but changes the grain size and lattice parameters. X-ray photoelectron spectroscopy (XPS) fitting results of Mn 2p peaks confirmed the coexistence of Mn 3+ and Mn 4+ ions which contribute to the double exchange interactions improving the ferromagnetic order in the samples. The magnetization's temperature and magnetic field dependences indicate a second-order ferromagnetic-paramagnetic transition of the ceramics. A significant magnetic entropy change near room temperature was observed for La 0.8 K 0.1 Pb 0.1 MnO3, showing considerable magnetocaloric properties . Furthermore, electron paramagnetic resonance spectroscopy (EPR) was also used to examine the ferromagnetic-paramagnetic transition.