Data from: Interplay of crystal structure and magnetic properties of the Eu5.08-xSrxAl3Sb6 solid solution

Zintl phases containing rare earth metals have gained attention due to
their magnetic, electronic, and thermoelectric properties. Eu5.08Al3Sb6 is
a new structure type (monoclinic space group C2/m) that can be described
as a pseudo-rock-salt EuSb motif with the Eu-centered Sb octahedra at the
origin of the unit cell, and on the C-face-center, containing either Eu
(8%) or an Al4 tetrahedron modeled as a dual tetrahedron (37.5 %). The
complete solid solution of Eu5.08-xSrxAl3Sb6 can be prepared; however, the
cation totals vacillate from 5 to 5.24 depending on the Al content. Al
K-edge XANES shows a shift to higher energy relative to Al metal, but at
slightly lower energy relative to AlSb, indicating an intermediate
oxidation state closer to +3 than 0. The lack of an Al K-edge shift with
the incorporation of Sr suggests that changes in Sr content do not have a
meaningful impact on the electronics of the Al tetrahedra. Investigation
of the solid solution structures provides evidence for classifying this
structure type as a polar intermetallic phase with variable composition.
Magnetization measurements were collected for the solid solution and show
complex magnetic ordering with competing ferromagnetic and
antiferromagnetic interactions as the Sr content increases.