Acta Phys. -Chim. Sin. ›› 1997, Vol. 13 ›› Issue (12): 1079-1083.doi: 10.3866/PKU.WHXB19971205

• ARTICLE • Previous Articles     Next Articles

Preparation and Pecuiar Magnetoresistance of La0.67Sr0.33FexMn1-xO3

Li Ya-Dong,Zhang Jian-Hui,Zhu Chang-Fei,Liu Wei,Xiong Cao-Shui,Zhou Yi,Qian Yi-Tai   

  1. Structure Reaserch Laboratory,Academia Sinica,Hefei 230026|Chemistry Department,University of Science and Technology of China,Hefei 230026|Laboratory of Interner Friction and Defects in Solid Academia Sinica,Hefei 230026
  • Received:1997-02-03 Revised:1997-05-05 Published:1997-12-15
  • Contact: Li Ya-Dong

Abstract:

 The Ln0.67Sr0.33Fe.Mn1-xO3(LSFMO)(0.05< x <0.33) systems have been synthesized by co-precipitation. The X-ray diffraction patterns indicates that these compounds are of single phase with rhombohedral structure. The resistivity of samples was measured in zero field and applied field (H=4000Oe) by a standard four-probe method. Large magnetoresistance (MR) was found in all samples. There is a resistivity transition peak in LSFMO (x ≦0.13) in which MR negative, the temperature (TP) at which the resistivity peak occurs decreases with the increasing of x. LSFMO (x=0.23) to which the large negative MR is still found is a semiconductor, It is unexpected that a peculiar alternative positive negative MR was found in LSFMO(x=0.33) which also is a semicondutor.

Key words: Co-precipitation, Route, Rhombohedral structure, Magnetoresistance