  La$_{0.4}$Na$_{0.6}$Fe$_2$As$_2$ single crystals have been grown out of an
NaAs flux in an alumina crucible and characterized by measuring magnetic
susceptibility, electrical resistivity, specific heat, as well as single
crystal x-ray and neutron diffraction. La$_{0.4}$Na$_{0.6}$Fe$_2$As$_2$ single
crystals show a structural phase transition from a high temperature tetragonal
phase to a low-temperature orthorhombic phase at T$_s$\,=\,125\,K. This
structural transition is accompanied by an anomaly in the temperature
dependence of electrical resistivity, anisotropic magnetic susceptibility, and
specific heat. Concomitant with the structural phase transition, the Fe moments
order along the \emph{a} direction with an ordered moment of
0.7(1)\,$\mu_{\textup{B}}$ at \emph{T}\,=\,5 K. The low temperature stripe
antiferromagnetic structure is the same as that in other
\emph{A}Fe$_{2}$As$_{2}$ (\emph{A}\,=\,Ca, Sr, Ba) compounds.
La$_{0.5-x}$Na$_{0.5+x}$Fe$_2$As$_2$ provides a new material platform for the
study of iron-based superconductors where the electron-hole asymmetry could be
studied by simply varying La/Na ratio.
