Structural, magnetic, electronic properties of the filled skutterudite EuFe$_4$As$_{12}$

The filled skutterudite EuFe$_4$As$_{12}$ has been synthesized and its structural, electronic, magnetic and thermodynamic properties have been carefully investigated. In this compound, the Fe and Eu moments order ferrimagnetically at T$_C$ = 151 K, the highest magnetic ordering temperature among filled skutterudite compounds. LDA+$U$ band structure calculations confirm the observed magnetic polarizations and suggest that the conduction electrons in EuFe4As12 have a large spin polarization, although slightly smaller than in the isostructural EuFe$_4$Sb$_{12}$. We present a joint experimental and theoretical study of the electronic and magnetic properties for both compounds, including the isostructural EuFe$_4$P$_{12}$, where the exchange of the pnictide can be considered as chemical pressure. To separate the influence of mere volume effects and a change of the pnictide we also studied the behaviour under hydrostatic pressure for EuFe$_4$As$_{12}$, both experimentally and theoretically.