AGING IN K1-XLIXTAO3 - A DOMAIN GROWTH INTERPRETATION

The aging behavior of the ac susceptibility of randomly substituted K1 -xLixTaO3 crystals reveals marked differences with spin glasses in tha t cooling rate effects are very important. The response to temperature steps (including temperature cycles) was carefully studied. A model b ased on thermally activated domain growth accounts for all the experim ental results, provided one allows for a large distribution of pinning energies, in such a way that ''slow'' and ''fast'' domains coexist. I nteresting similarities with deeply supercooled liquids are underlined . [S0031-9007(98)07804-1].