Inhomogeneous magnetic state in manganites—experimental aspects

Abstract The crystal and magnetic structure as well as elastic, magnetic, and electrotransport properties of La 0.88 MnO x (2.82⩽ x ⩽2.96) and Nd 1− x Ca x MnO 3 (0⩽ x ⩽0.2) manganites have been investigated as a function of Mn 4+ content by X-ray, neutron diffraction, Young's modulus, magnetization, and resistivity measurements. The gradual transition from an orbitally ordered state to an orbitally disordered one is observed with increasing temperature or Mn 4+ content. The magnetic properties of the samples have been found to correlate with the type of orbital state. The dynamic orbital correlations favor ferromagnetic state, while A-type antiferromagnetic state is typical for the static Jahn–Teller distortions. The properties are discussed in the framework of the structurally driven phase separation model.