| 학회 |
한국재료학회 |
| 학술대회 |
2021년 가을 (11/24 ~ 11/26, 경주 라한호텔) |
| 권호 |
27권 2호 |
| 발표분야 |
A. 전자/반도체 재료 분과 |
| 제목 |
Effect of A-B-site Co-Doping on structure, magnetic and magnetocaloric properties of La1.2Pr0.2Ca1.6Mn1.9Cr0.1O7 Ruddlesden-Popper perovskites |
| 초록 |
Here, an optimized substitution of Pr and Cr was performed in LCMO simultaneously in place of La and Mn, in order to modify the magnetic and magnetocaloric properties. For this purpose, the samples were synthesized through solid-state reaction method. The XRD peaks were correspond to the tetragonal I4/mmm phase of Ruddlesden-Popper manganites, besides the secondary La2O3 and MnO2 were also observed with the bilayer phase. Furthermore, the diffraction peaks shifted towards the lower values of 2θ. The shift in XRD peaks elucidate the expansion in the unit cell parameter. The expansion in unit cell parameters here ascribed to the large Cr ionic radii compared to the Mn. The microstructure analysis of the samples revealed clear shrinkage of grains, with the ambiguous grain boundaries. The shrinkage behavior and increase in porosity with the doping are indicative to the fact that both Cr-and Pr in LCMO influences the sintering behavior of the material. The M-T curve of these compounds exhibit multiple step-like transitions. The multiple transitions were ascribed to fact that the impurity phases contribute in the magnetic transition of the samples and express the separate transition within the paramagnetic phase of the parent compound. The magnetic entropy of co-doped samples bifurcated at lower field values and the distinction vanished at high values of applied field. The multiple entropy peaks marked that the inhomogeneous states had a significant effect on the magnetocaloric parameters. The maximum entropy value of 3.12 J/kgK and 2.2 J/kgK was achieved for parent and co-doped sample respectively. Similarly, the maximum RCP value was observed to be 113 J/kg at 2.5 T applied for co-doped sample and the RCP values decreased up to a value of ~100J/kg for parent compound. |
| 저자 |
Akshay Kumar1, Kavita Kumari2, MinJi Shin3, Seok Hwan Huh4, Bon Heun Koo5
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| 소속 |
1Department of Materials Convergence and System Engineering, 2Changwon National Univ., 3Changwon, 4Gyeongnam, 551140 |
| 키워드 |
Magnetocaloric properties; Ruddlesden-Popper manganites; microstructure analysis; relative cooling power (RCP); magnetic entropy
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| E-Mail |
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