Magnetic and electric properties ofLa1−δMnO3

The magnetic phase diagram of ${\mathrm{La}}_{1-\delta }{\mathrm{MnO}}_3$ powdered samples has been studied as a function of $\delta$ in the low doping range $(\delta <0.1).\mathrm{}{\mathrm{La}}_{0.97}{\mathrm{MnO}}_3$ has a canted magnetic structure at low temperature $\left(\theta \simeq 130°\right).\mathrm{}$ Above $T_C=118\mathrm{}\hspace{0.5em}\mathrm{K},$ it becomes a paramagnet with a huge effective magnetic moment ${\mu }_{\mathrm{eff}}=6.0\mathrm{}{\mu }_B,$ reflecting the presence of magnetoelastic polarons which are not affected by the magnetic field (up to 20 T) or the temperature ${1.2T}_C<T<\mathrm{}{2.5T}_C.$ When $\delta$ is increased to $\delta =0.09,$ the system becomes fully ferromagnetic below $170\hspace{0.5em}\mathrm{K}$ but remains insulating down to the lowest temperature.