YLiF4: Er3 + was synthesized by hydrothermal method. Concentration of Er3 + is changed from 0 to 5 %. The absorption of Er3+ in all samples from 200 to 1200 nm
The system La0.67-x ErxSr0.33 MnO3 ( x =0.00, 0.10, 0.20) was investigated through the measurements of M-T, ρ-T and MR-T curves. The experiment results show th