Rare earth regenerator material and regenerator and refrigerator provided with the same

摘要

The present invention provides a regenerator material having a high specific heat in a temperature range of 10K or higher (particularly a temperature range of 10 to 20K), and a regenerator and refrigerator equipped with the regenerator. Specifically, the present invention relates to the general formula (1) Er _1-x R _x Ni _{1 + α} (1) [Wherein, x represents 0 x 1, and α represents −1 α 1. R represents at least one selected from Y and lanthanoid elements (excluding Er). ] The rare earth regenerator material characterized by these, and the regenerator and refrigerator provided with this are provided.