Giant magnetoresistance and related properties of rare earth manganates and related systems

Rare earth manganates of the formula Ln1−x A x MnO3 become ferromagnetic and undergo an insulator-metal transition around the Curie temperature, T c , when the Mn4+ content is around 30%. These materials also show GMR especially around T c . Various features affecting GMR in these materials and certain novel features such as charge-ordering exhibited by manganates are discussed.