Correlation Between Magnetovolume and Colossal Magnetoresistance Effects in Terbium Doped La-Sr-Mn-O Perovskite

(La_0.67Tb_0.33)_2/3Sr_1/3MnO₃ has been studied in order to probe mechanisms responsible for the giant magnetore-sistance ratios and the lattice effect in this kind of compound. The experiment has shown a strong connection between the magnetotransport and magnetovolume properties. An applied magnetic field not only gives rise to a large negative magnetoresistance (-900%) but also produces two different magnetovolume effects which reflect two different magnetostriction mechanisms in the compound.