Itinerant-electron metamagnetic transition and large magnetovolume effects inLa(FexSi1−x)13compounds

Abstract

Magnetic properties and magnetovolume effects have been investigated for itinerant-electron metamagnetic $\mathrm{La}({\mathrm{Fe}}_x{\mathrm{Si}}_{1-x}{)}_{13}$ compounds. At the Curie temperature $T_{C1\mathrm{}},$ a first-order magnetic phase transition takes place in the concentration range $0.86<~x<~\mathrm{0.88.}$ With increasing Fe concentration, the Curie temperature decreases and the critical temperature of the itinerant-electron metamagnetic (IEM) transition increases, accompanied by a more sharp IEM transition. For the compound with $x=0.88,$ a large volume change of about 1% follows the thermal induced transition at $T_{C1\mathrm{}}.$ The value of $T_{C1\mathrm{}}$ is significantly decreased by applying hydrostatic pressure, whereas the pressure dependence of the spontaneous magnetization is relatively small. These results are explained by the negative mode-mode coupling among spin fluctuations.