Effects of H-doping in Y2Fe17 compounds on the structure, magnetic properties, and Mössbauer effect.

We introduce a novel water bath hydrogenation process designed to enhance the magnetic properties and hyperfine field of Y₂Fe₁₇. The core of this process lies in the successful preparation of a new compound Y₂Fe₁₇H_3.5 by introducing hydrogen in a mild water bath environment, accomplished by a chemical reaction between calcium, Y₂Fe₁₇, and ammonium acetate solution at room temperature and pressure. After hydrogen doping, cell volume expansion increased from 778.511 to 795.383 ų, and notably, lattice expansion is anisotropic. Furthermore, saturation magnetization is increased from 103 to 134.93 emu/g, Curie temperature is increased from 320 to 461 K, and the average hyperfine field is increased from 18 to 25 T. The improvement in magnetic properties is due to the increase in Fe–Fe distance, which according to the Bethe–Slater curve leads to stronger Fe–Fe exchange interactions and enhancing ferromagnetic interactions. This work not only proposes the novel rhombohedral Y₂Fe₁₇H_3.5 with excellent magnetic properties, but also provides a new method for hydrogen doping in Y₂Fe₁₇ which lays the foundation of fundamental solid state physics for further research. [ABSTRACT FROM AUTHOR]