The influence of a partial substitution of Ce or Pr on the magnetocaloric effects due to the itinerant electron metamagnetic transition of La(Fe xSi1-x)13 has been investigated. The partial substitution of R = Ce or Pr for La in La1-zRz(Fe 0.88Si0.12)13 results in the decrease of the Curie temperature Tc with decreasing the lattice constant. For the partial substitution of Ce, the change in TC is mainly attributed to the magnetovolume effect caused by small radius of Ce atoms. The influence of Pr moment on TC is also pointed out. The increase of the isothermal entropy change δSm with decreasing TC is confirmed by both the partial substitution and application of hydrostatic pressure, although the increment of δSm by the latter is smaller than that by the former. The spin-wave dispersion coefficient Dsw is slightly increased after partial substitutions in contrast to the application of hydrostatic pressure, and the reduction of thermal demagnetization up to T C brings about the enhancement of δSm. Accordingly, the increase in ferromagnetic stability due to the change in 3d band structure enhances δSm, in addition to the magnetovolume effect. The hysteretic behavior of the IEM transition is reduced by decreasing Fe concentration, whereas δSm is enhanced by the partial substitution. Consequently, a marked reduction of hysteresis loss with retaining the large magnitude of δ Sm is demonstrated in La 1-zRz(Fe0.96Si0.14)13 (R = Ce and Pr). We have also presented that TC in the partially substituted compounds with Ce or Pr is increased up above room temperature by hydrogen absorption, keeping the enhancement of MCEs by the partial substitution.
- Itinerant-electron metamagnetic transition
- Magnetic refrigerantion
- Magnetocaloric effect
- Partial substitution
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering