Abstract:
Multiferroics are materials in which magnetism and ferroelectricity coexist. They are of fundamental interest to understand how magnetic ordering can affect electric dipolar
ordering and vice-versa. Moreover, they are of applied interest because they allow various types of novel magnetic and electric device structures. A variant of multiferroic
materials called multiglass has also been reported ; in which both the magnetic and polar orders are frozen. A multiglass is characterised by the coexistence of a magnetic spin glass and a dielectric glass phase . A thermodynamic glass transition is observed
only in the materials with quenched disorder but experimentally, it is observed that some
of the disorder-free pyrochlore materials manifest spin glass transition , which is identical to the conventional one with quenched disorder. Very recently, dynamical simulations have been used to suggest that this class of disorder-free pyrochlores could
harbour a manifestation of a spin-orbital glass state, a phenomenon characterized by the divergence of the non-linear magnetic and dielectric susceptibilities .This would implicitly mean that these geometrically frustrated pryochlores are multiglasses. This project was aimed to investigate the potential multi-glass state in two pyrochlore oxides;
Y2Mo2O7 and Pr2Ru2O7. These specimens synthesized using the solid state ceramic
route were evaluated using a combination of structural characterization tools, as well as linear and nonlinear dielectric and magnetic susceptibility measurements.
