Wednesday, January 24, 2007

Preliminary results by ananlyzing LCMO (16%-22%)















This is the Sigma^2 vs T for different samples with doping level x = 16%,18%,20%,22%.

A sharp increase in Sigma^2 (Sigma is the width of the Mn-O pair distribution function "PDF")near Tc.

The magnitude of the step decreases rapidly with decreasing x.

The value of Sigma^2 at low T is close to the value for zero-point motion for x = 22%, but increases substantially for lower x, which indicates that in the magnetized state there is either a large Jahn-Teller distortions or a static distortion which remains at low T.

The end compound LaMnO3 has a large J-T distortion, so we think it's caused by J-T distortion.














Also the magnetization at low T is small for lower x, indicating that not all of the sample is ferromagnetic, regions of antiferromagnetism may remain.