The effects of hydrostatic pressure and magnetic field on the electrical resistance of the Kondo-like perovskite manganese oxide, ${\mathrm{La}}_{0.1}{\mathrm{Ce}}_{0.4}{\mathrm{Sr}}_{0.5}\mathrm{Mn}{\mathrm{O}}_3$ with a ferrimagnetic ground state, have been investigated up to $2.1\mathrm{GPa}$ and $9\mathrm{T}$. In this compound, the Mn moments undergo a double exchange mediated ferromagnetic ordering at $T_C\sim 280\mathrm{K}$ and there is a resistance maximum, $T_{\max }$ at about $130\mathrm{K}$, which is correlated with an antiferromagnetic ordering of cerium with respect to the Mn-sublattice moments. Under pressure, the $T_{\max }$ shifts to lower temperatures at a rate of $d{T}_{\max }∕dP=-162\mathrm{K}∕\mathrm{GPa}$ and disappears at a critical pressure $P_c\sim 0.9\mathrm{GPa}$. Further, the coefficient, $m$ of $-\ln T$ term due to Kondo scattering decreases linearly with increase of pressure showing an inflection point in the vicinity of $P_c$. These results suggest that cerium undergoes a transition from ${\mathrm{Ce}}^{3+}$ state to a ${\mathrm{Ce}}^{4+}∕{\mathrm{Ce}}^{3+}$ mixed valence state under pressure. In contrast to the pressure effect, the applied magnetic field shifts $T_{\max }$ to higher temperatures, presumably due to enhanced ferromagnetic Mn moments.

• Received 28 April 2005

DOI:https://doi.org/10.1103/PhysRevB.72.060402