Epitaxial Growth of Gd_(0.67) Ca_(0.33) MnO_3 Thin Films by Laser Ablation

摘要

Gd_(0.67) Ca_(0.33)MnO_3 ( GCMO) thin films grown by laser ablation on SrTiO_3 (100) (STO) substrates was studied. Films are highly crystallized, very well epitaxial and single-phased. The ordering magnetic temperature (T_c) of the films is much higher than the value of bulk samples of similar composition. It is found that the GCMO film exhibits a reversal of its magnetization at low temperature when cooled under a magnetic field. The negative magnetization is a consequence of the rapid increase ( ～ 1/T) with decreasing temperature of the magnetization of a sublat-tice aligned antiparallel to the local field, relative to the magnetic contribution of a second sublattice which is a-ligned parallel to the applied field.