| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a regenerator material for extremely low temperatures, which exerts good mechanical properties with high reproducibility against mechanical vibration, charging pressure, and the like. <P>SOLUTION: A predetermined amount of magnetic regenerator material particles is extracted from prepared magnetic regenerator material particles. A rate of particles that are fractured when a compressive stress of 5 MPa is applied to the extracted magnetic regenerator material particle population is measured. Magnetic regenerator material particles having such a rate (of particles that are fractured when a compressive stress of 5 MPa is applied) of 1 wt.% or less are selected. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
