Electrical transport in disordered and ordered magnetic domains under pressures and magnetic fields

Magnetic M( T, H, P) and electrical transport.( T, H, P) measurements in a strong spin-lattice-charge coupled La(0.7)Ca(0.3)MnO(3) system have been conducted. The application of H and P leads to the formation of different magnetic domain structures in the vicinity and below the polaronic-to-ferromagnetic transition temperature. The charge mobility is more sensitive to the variation of the spatial wave function overlap between Mn(3+) eg and O(2-) 2p orbitals due to the applied compacting pressure rather than the relative spin orientation between neighbouring Mn ions when the magnetic field is applied. In spite of the presence of different magnetic domain structures due to the sample history, the effect of magnetic field and pressure is less pronounced at lower temperatures on electrical transport properties.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Brazilian agencies FAPESP[05/53241-9]

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Brazilian agencies FAPESP[07/01039-7]

CNPq[473932/2007-5]

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)