Magnetic, electronic and structural properties of the filled skutterudite EuFe$_{4}$As$_{12}$

The europium iron arsenide EuFe$_{4}$As$_{12}$ with filled skutterudite structure has been synthesized and its structural, electronic, magnetic and thermodynamic properties have been investigated. The Fe and Eu moments order ferrimagnetically at T$_{C}$ = 151 K, the highest magnetic ordering temperature among filled skutterudite compounds. LDA band structure calculations confirm the observed magnetic polarizations and suggest that the conduction electrons in EuFe$_{4}$As$_{12}$ have a large spin polarization, albeit lower than in the isostructural EuFe$_{4}$Sb$_{12}$. We present a comparative 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.