Pressure-induced anomalies in itinerant-electron metamagnetic properties around the critical end point inLa(Fe0.89Si0.11)13

Abstract

Pressure-induced anomalies around the critical end point in an itinerant-electron metamagnetic $\mathrm{La}({\mathrm{Fe}}_{0.89}{\mathrm{Si}}_{0.11}{)}_{13}$ compound have been investigated. The Curie temperature ${T}_{\mathrm{C}}$ is decreased from 189 to $0\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ by applying a critical pressure ${p}_{\mathrm{C}}=1.3\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. The relation ${T}_{\mathrm{C}}\ensuremath{\propto}({p}_{\mathrm{C}}\ensuremath{-}p{)}^{0.5}$ is explained by the spin-fluctuation theory based on the Landau expansion. A susceptibility maximum appears at ${T}_{\mathrm{max}}\ensuremath{\sim}70\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ above $p=1.2\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. On the other hand, the critical point $({T}_{0},{\ensuremath{\mu}}_{0}{H}_{0})$ of the transition is lowered to ${T}_{0}=14\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ and ${\ensuremath{\mu}}_{0}{H}_{0}=2.5\phantom{\rule{0.3em}{0ex}}\mathrm{T}$ at $1.4\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$, showing no static ferromagnetic moment in the field-induced state below ${T}_{0}$.