Phonon evidence for a partial, re-entrant spin reorientation near room temperature in LaFe$_{1-x}$Ni$_x$O$_3$
Spin reorientation near room temperature offers a route to controlling antiferromagnetic order, yet LaFeO$3$, which lacks a magnetic rare-earth ion, is generally expected to retain its spin orientation along the $a$ axis below $T{\mathrm N}\approx740$~K. Here, we investigate LaFe$_{1-x}$Ni$_x$O$_3$ ($x=0$ and 0.1) usin...