Corrosion behavior and magnetocaloric property of pure phase La1-xCexFe11.5Si1.5 (x=0.1,0.2,0.3) compounds

J I E Hu; H A O T I A N Liu; X I N Y A O Zhang; Z H I Wang; Z H I G A N G Yang; M E N G N A N Feng; X U E P E N G Shi

doi:10.1016/j.heliyon.2024.e25169

Corrosion behavior and magnetocaloric property of pure phase La_1-xCe_xFe_11.5Si_1.5 (x=0.1,0.2,0.3) compounds

Heliyon. 2024 Jan 24;10(3):e25169. doi: 10.1016/j.heliyon.2024.e25169. eCollection 2024 Feb 15.

Authors

J I E Hu^{1

2

3}, H A O T I A N Liu¹, X I N Y A O Zhang¹, Z H I Wang¹, Z H I G A N G Yang¹, M E N G N A N Feng¹, X U E P E N G Shi¹

Affiliations

¹ School of Materials Science and Engineering, ShiJiaZhuang TieDao University, Shijiazhuang, 050043, China.
² Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
³ Zhejiang LINIX Motor Co., Ltd.，Jinhua, 317525, China.

Abstract

To further study the corrosion mechanism of pure phase La(Fe,Si)₁₃, Ce were added into the LaFe_11.5Si_1.5 compounds to facilitate phase formation and improve corrosion resistance and magnetic properties. The corrosion test conducted on the pure phase La_1-xCe_xFe_11.5Si_1.5 (x = 0.1, 0.2, 0.3) revealed a significant number of minute corrosion pits with irregular shapes such as round, square and triangular after only 1 h of corrosion in tap water. However, in the case of La_0.7Ce_0.3Fe_11.5Si_1.5 compound, the number of corrosion pits was significantly lower. Potentiodynamic polarization curves showed that Ecorr goes up from -0.76 V to -0.59 V, and the Icorr goes down from 4.92 × 10^-6 A/cm² to 2.46 × 10^-6A/cm² as a result of Ce addition from 0.1 to 0.3. With the increase of Ce content, the corrosion resistance of La_1-xCe_xFe_11.5Si_1.5 compounds was improved. Adding Ce element in the LaFe_11.5Si_1.5 compounds can also enhance the magnetocaloric effect. Significant extra spike-shaped peaks were observed on the M-H curves of La_0.8Ce_0.2Fe_11.5Si_1.5 and La_0.7Ce_0.3Fe_11.5Si_1.5, indicating a strong first-order magnetic phase transition. Furthermore，-△S_M values improved from 21.2 J/kg K to 51.6 J/kg K by increasing Ce from 0.1 to 0.3.

Keywords: Corrosion behavior; Magnetic materials; Magnetocaloric property; Pure phase La1-xCexFe11.5Si1.5 (x=0.1,0.2,0.3).