Study of Magnetic Properties and Specific Heat on Magnetic Regenerators Er(Ni_1-xCo_x)(x-0,0.1,0.2)

Magnetic regenerators Er(Ni_1-xCo_x)(x-0,0.1,0.2) have been studied Curie temperature of Er(Ni_1-xCo_x)(x-0,0.1,0.2) decreases to the temperature range below 10 K by replacing Co with Ni partially. Magnetic regenerators Er(Ni_1-xCo_x)(x-0,0.1,0.2) have larger specific heats than Pb and other Er-Ni magnetic regenerators. It is shown that effective value J of total angular momentum of Er⁺³ ion is about 3/2 from the curves of the specific heats.