Spin Polarons at High Temperatures in Undoped Lanthanum Manganites
Magnetic properties of undoped samples of lanthanum manganites in the temperature range 77-650K are reported. The ferromagnetic Curie temperature increases when the unit-cell volume decreases and the number of cation defects increases. Uncorrelated polarons and noninteracting moments of Mn ions are present in the region TC < T < 440K. Above 2TC < 440 K < T, the nonstoihiometric LaMnO3 compound passes into the homogeneous paramagnetic state.
T.I. Arbuzova et al., "Spin Polarons at High Temperatures in Undoped Lanthanum Manganites", Solid State Phenomena, Vols. 168-169, pp. 473-476, 2011