학술논문

Role of Griffiths phase on magnetocaloric properties and critical behavior of half-doped manganites [La0.5Sr0.5-xCaxMnO3(x = 0, 0.25, 0.5)].
Document Type
Academic Journal
Author
Mandal S; Department of Physics, National Institute of Technology Patna, Patna, Bihar 800005, India.; Mohanty S; Department of Physics, National Institute of Technology Patna, Patna, Bihar 800005, India.; Chakravarty S; UGC DAE CSR, Kalpakkam Node, Tamil Nadu 603104, India.; Mukherjee S; Department of Physics, National Institute of Technology Patna, Patna, Bihar 800005, India.
Source
Publisher: American Institute of Physics Country of Publication: United States NLM ID: 0375360 Publication Model: Print Cited Medium: Internet ISSN: 1089-7690 (Electronic) Linking ISSN: 00219606 NLM ISO Abbreviation: J Chem Phys Subsets: PubMed not MEDLINE; MEDLINE
Subject
Language
English
Abstract
In this article, a comprehensive study of the effect of calcium substitution on structural magnetic, magnetocaloric properties, and role of Griffiths phase on magnetocaloric properties of half-doped manganites La0.5Sr0.5-xCaxMnO3(x=0,0.25,0.5)] have been presented. A structural phase transition I4/mcm - Pbnm is observed in the whole series. The system exhibits two magnetic transitions for Ca-00 and Ca-25, whereas only one phase transition is observed for Ca-50. Paramagnetic (PM)-ferromagnetic (FM) transition is observed in the whole series and ferromagnetic (FM) - antiferromagnetic (AFM) phase transition is only observed in Ca-25. Interestingly, short range FM clusters exist in the PM matrix of Ca-50, which is a signature of Griffiths phase (GP). The confirmation of GP has been carried out by performing iso-field magnetization measurements at 200 Oe, 500 Oe, and 1 kOe, respectively. Further magnetocaloric properties have been discussed on the basis of isothermal magnetization curves recorded at certain temperature intervals. Calcium substitution favors the enhancement of magnetic entropy change in the series, especially for Ca-50, a magnetic entropy change of 4.5 J/(kg K) with relative cooling power of 180 J/kg under 5 T magnetic field was observed. Iso-field magnetization and magnetocaloric effect along with critical behavior analysis have been carried out to probe the GP and other inhomogeneities present in the respective series.
(© 2024 Author(s). Published under an exclusive license by AIP Publishing.)