Suppression of aqueous corrosion of La(Fe_(0.88)Si_(0.12))_(13) by reducing dissolved oxygen concentration for high-performance magnetic refrigeration

摘要

The itinerant-electron metamagnetic transition of La(Fe_(0.88)Si_(0.12))_(13) becomes indistinct after immersion in distilled-water containing about 8 ppm of the dissolved oxygen (DO) concentration because of aqueous corrosion. However, the aqueous corrosion of La(Fe_(0.88)Si_(0.12))_(13) is significantly suppressed by reducing the DO concentration. Thus, isothermal magnetic entropy change after immersion for 30 days in deaerated distilled-water with a DO concentration less than 0.1 ppm is larger than that after immersion for 5 days in distilled-water containing about 8 ppm of the DO concentration. Consequently, the reduction of the DO concentration is effective for preservation of the excellent magnetocaloric effects of La(Fe_(0.88)Si_(0.12))_(13) in an aqueous solution, which is a promising heat transfer fluid of room-temperature magnetic refrigeration.