Synchrotron X-Ray sattering studies of charge and spin stripes in manganites

摘要

Using synchrotron x-ray scattering, we have studied the modulated structures caused by charge and spin stripes in the manganites of Bi_(0.24)Ca_(0.76)MnO_3 and Nd_(1/2)Sr_(1/2)MnO_3 in detail. Weak satellite reflections were observed below the transition temperatures of T_(CO)=241 K for Bi_(0.24)Ca_(0.76)MnO_3 and T_(CO)=160K for Nd_(1/2)Sr_(1/2)MnO_3, respectively, associated with the charge and spin ordering of Mn~(3+) and Mn~(4+) into charge and spin stripes within the perovskite structure. Transition to the charge stripe phase was observed to be the first-order displaying the hysteresis behaviour and accompany the first-order structural phase transition in both materials. In addition, the spin and orbital stripes in Nd_(1/2)Sr_(1/2)MnO_3 were further confirmed by the resonant effect at the incident energy of the Mn K-edge.