Spectacular Magneto-Related Properties of Complex Oxides

Abstract

Perovskite manganites display unusual correlations between magnetic,electronic, and structural properties that are caused by strongelectron-electron and electron-phonon interactions. In this paper wediscuss spectacular magneto-related structural, resistive, andthermo-caloric properties originating from magnetic, orbital, and chargeordering. Detailed neutron diffraction, striction, and magneticmeasurements demonstrate a wealth of novel behavior observed for thesecompounds: the structural transformation induced by ferromagnetictransition, the structural transformation induced at fixed temperatureby application of magnetic field, and the large magnetocaloric andcolossal magnetoresistive effects observed near the coupledferromagnetic and metal-insulator transitions. Detailed study of thecomplex synthesis-structure-property relations hip a allows control ofseveral of new properties and promises fascinating possibilities fortechnological applications of manganites as sensitive sensors ofmagnetic field, and working materials in magnetic refrigeration.