In half-doped $\mathrm{P}{\mathrm{r}}_{0.50}{A}_{0.50}\mathrm{Co}{\mathrm{O}}_3$ metallic perovskites, the spin-lattice coupling brings about distinct magnetostructural transitions for $A=\mathrm{Ca}$ and $A=\mathrm{Sr}$ at temperatures close to ∼100 K. However, the ground magnetic properties of $\mathrm{P}{\mathrm{r}}_{0.50}\mathrm{S}{\mathrm{r}}_{0.50}\mathrm{Co}{\mathrm{O}}_3$ (PSCO) strongly differ from $\mathrm{P}{\mathrm{r}}_{0.50}\mathrm{C}{\mathrm{a}}_{0.50}\mathrm{Co}{\mathrm{O}}_3$ ones, where a partial $\mathrm{P}{\mathrm{r}}^{3+}$ to $\mathrm{P}{\mathrm{r}}^{4+}$ valence shift and Co spin transition makes the system insulating below the transition. This paper investigates and describes the relationship between the $Imma\to I4/mcm$ symmetry change [Padilla-Pantoja, García-Muñoz, Bozzo, Jirák, and Herrero-Martín, Inorg. Chem. 53, 12297 (2014)] and the original magnetic behavior of PSCO versus temperature and external magnetic fields. The FM1 and FM2 ferromagnetic phases, above and below the magnetostructural transition ($T_{S1}\sim 120K$) have been investigated. The FM2 phase of PSCO is composed of [100] FM domains, with magnetic symmetry $I{m}^{\prime }{m}^{\prime }a$ ($m_x\ne 0, m_z=0$). The magnetic space group of the FM1 phase is $F{m}^{\prime }{m}^{\prime }m$ (with $m_x=m_y$). Neutron data analyses in combination with magnetometry and earlier reports results agrees with a reorientation of the magnetization axis by ${45}^{\circ }$ within the $ab$ plane across the transition, in which the system retains its metallic character. The presence below $T_{S1}$ of conjugated magnetic domains, both of $F{m}^{\prime }{m}^{\prime }m$ symmetry but having perpendicular spin orientations along the diagonals in the $xy$ plane of the tetragonal unit cell, is at the origin of the anomalies observed in the macroscopic magnetization. A relatively small field ${\mu }_{0}H\left[\perp z\right]\gtrsim 30\mathrm{mT}$ is able to reorient the magnetization within the $ab$ plane, whereas a higher field (${\mu }_{0}H[\parallel z]\gtrsim 1.2\mathrm{T}$ at 2 K) is necessary to align the Co moments perpendicular to the $ab$ plane. Such a spin reorientation, in which the orbital and spin components of the Co moment rotate joined by ${45}^{\circ }$, was not observed previously in analogous cobaltites without praseodymium.

• Received 19 March 2016

DOI:https://doi.org/10.1103/PhysRevB.94.014411