Reentrant metallic transition at a temperature above Tc at the breakdown of cooperative Jahn-Teller orbital order in perovskite manganites -: art. no. 132413

We report an interesting reentrant metallic resistivity pattern beyond a characteristic temperature T* which is higher than other such characteristic transition temperatures like T-c (Curie point), T-N (Neel point), T-CO (charge order onset point) or T-OO (orbital order onset point) in a range of rare-earth perovskite manganites (RE(1-x)A(x)MnO(3); RE=La, Nd, Y; A=Sr, Ca; x=0.0-0.5). Such a behavior is normally observed in doped manganites with doping level (x) higher than the critical doping level x(c) (=0.17-0.22) required for the metallic ground state to emerge and hence in a system where cooperative Jahn-Teller orbital order has already undergone a breakdown. However, the observation made in the La1-xCaxMnO3 (x=0.0-0.3) series turns out to be an exception to this general trend.