Jahn-Teller-induced crossover of the paramagnetic response in the singly valent e_g system LaMn₇O₁₂

TY - JOUR

T1 - Jahn-Teller-induced crossover of the paramagnetic response in the singly valent eg system LaMn7O12

AU - Cabassi, R.

AU - Bolzoni, F.

AU - Gilioli, E.

AU - Bissoli, F.

AU - Prodi, Andrea

AU - Gauzzi, A.

PY - 2010/6/9

Y1 - 2010/6/9

N2 - We investigate the high-temperature magnetic and transport properties of LaMn7O12, which displays a similar perovskitelike structure and the same single-valent Mn3+ properties of LaMnO 3 but a much simpler Jahn-Teller (JT) distortion at TJT =650K. We find that the magnetic response of LaMn7O12 is similar to that of LaMnO3 below TJT, but strikingly different in the undistorted phase above TJT, where the Curie-Weiss susceptibility is strongly suppressed. Electrical resistivity and thermopower measurements unveil a concomitant crossover from nonadiabatic to adiabatic small polaron regime. This suggests that the above suppression is due to low-spin electron-hole dimers formed by the eg charge transfer between Mn sites and stabilized by the slow JT dynamics above TJT.

AB - We investigate the high-temperature magnetic and transport properties of LaMn7O12, which displays a similar perovskitelike structure and the same single-valent Mn3+ properties of LaMnO 3 but a much simpler Jahn-Teller (JT) distortion at TJT =650K. We find that the magnetic response of LaMn7O12 is similar to that of LaMnO3 below TJT, but strikingly different in the undistorted phase above TJT, where the Curie-Weiss susceptibility is strongly suppressed. Electrical resistivity and thermopower measurements unveil a concomitant crossover from nonadiabatic to adiabatic small polaron regime. This suggests that the above suppression is due to low-spin electron-hole dimers formed by the eg charge transfer between Mn sites and stabilized by the slow JT dynamics above TJT.

U2 - 10.1103/physrevb.81.214412

DO - 10.1103/physrevb.81.214412

M3 - Journal article

SN - 2469-9950

VL - 81

SP - 214412

JO - Physical Review B

JF - Physical Review B

IS - 21

ER -