Effect of Mo on corrosion resistance and magnetic property of LaFe_11.5Si_1.5 magnetic refrigeration materials

Abstract

The effect of Mo on phase formation, corrosion resistance and magnetic property of LaFe11.5Si1.5 magnetic refrigeration materials were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), electrochemical workstation and vibrating sample magnetometer (VSM). The results show that the amount of α-Fe phase and La-rich phase increases with the increase of Mo content. Mo is distributed in both NaZn13-type structure phase (1:13 phase for short) and α-Fe phase, but it does not appear in the La-rich phase. The studies on the corrosion resistance show that the corrosion potential increases and corrosion current density decreases with the increase of Mo content from x=0 to x=0.2, which indicate that the thermodynamic stability and corrosion resistance are improved. However, the corrosion resistance decreases while x increases to 0.3. The maximum magnetic entropy changes of LaFe11.5-xMoxSi1.5 under a magnetic field change of 0-3 T are about 18.51 J/(kg·K)(x=0),16.24 J/(kg·K)(x=0.1) and 5.68 J/(kg·K)(x=0.2), respectively.

Keywords

• magnetic refrigeration material
• la(fe,si)₁₃
• corrosion resistance
• magnetic property