Enhanced room temperature magnetoresistance in La0.7 Ca0.2 Sr0.1 MnO3/Ag composites

The effect of added Ag on the electro-magnetic properties and enhanced room temperature magnetoresistance in (La0.7Ca0.2Sr0.1MnO3)1−x/Agx composites has been studied systematically. According to the results of x-ray diffraction, scanning electron microscopy and magnetic measurement, we can suggest that Ag segregates at the grain surface of La0.7Ca0.2Sr0.1MnO3. The results of electronic measurements show that the intrinsic insulator/metal transition temperature (TP) does not change, which is in accordance with the results for the Curie temperature (TC). It is very interesting to note that the magnetoresistance at room temperature is enhanced, which is encouraging for potential applications. These phenomena can be explained by considering that Ag, which segregated at the grain boundaries or surfaces, does not change the intrinsic structure of La0.7Ca0.2Sr0.1MnO3 and lead to a modification of grain boundaries.

[1]  H. Salamati,et al.  Structural, magnetic and transport properties of La0.8Sr0.2MnO3/xNiO composites , 2006 .

[2]  H. D. Yang,et al.  Study of grain boundary contribution and enhancement of magnetoresistance in La0.67Ca0.33MnO3/V2O5 composites , 2005 .

[3]  L. Mei,et al.  Electrical properties and room temperature magnetoresistance of La0.67(Ca0.65Ba0.35)0.33MnO3/Agx composites , 2005 .

[4]  Z. M. Song,et al.  Structure and electrical properties in La2/3(Ca1-xSrx)1/3MnO3 films , 2005 .

[5]  Xiukun Hu,et al.  Colossal magnetoresistance of bulk Ag-doped Nd0.7Sr0.3MnO3 two-phase composites , 2005 .

[6]  L. Mei,et al.  Enhancements of magnetoresistance in Bi- or Ti-doped La0.67Ba0.33MnO3 , 2005 .

[7]  C. Srivastava,et al.  Magnetic and electrical transport properties of La~0~.~6~7Ca~0~.~3~3MnO~3 (LCMO):xZnO composites , 2004 .

[8]  T. Tang,et al.  Giant magnetoresistance of bulk polycrystalline La0.833Na0.167MnO3 with Ag2O addition , 2003 .

[9]  O. Lebedev,et al.  Doping of interfaces in (La0.7Sr0.3MnO3)1−x:(MgO)x composite films , 2002 .

[10]  Chunhua Yan,et al.  Large enhancement in room-temperature magnetoresistance and dramatic decrease in resistivity in La0.7Ca0.3MnO3–Ag composites , 2002 .

[11]  J. Kreisel,et al.  Raman scattering study of La0.7Sr0.3MnO3/SrTiO3 multilayers , 2002 .

[12]  R. Das,et al.  Solution sol–gel processing and investigation of percolation threshold in La2/3Ca1/3MnO3:xSiO2 nanocomposite , 2002 .

[13]  C. Ong,et al.  Low-field magnetoresistance in nanosized La0.7Sr0.3MnO3/Pr0.5Sr0.5MnO3 composites , 2001 .

[14]  C. Mitra,et al.  Enhanced room-temperature magnetoresistance in La0.7Sr0.3MnO3-glass composites , 2001 .

[15]  A. Berenov,et al.  Colossal magnetoresistance in screen printed La0.67Ca0.33MnO3 thick films , 2000 .

[16]  Jimeng Sun,et al.  Enhanced magnetoresistance in sintered granular manganite/insulator systems , 1999 .

[17]  B. Martínez,et al.  ENHANCED FIELD SENSITIVITY CLOSE TO PERCOLATION IN MAGNETORESISTIVE LA2/3SR1/3MNO3/CEO2 COMPOSITES , 1999 .

[18]  A. Maignan,et al.  Substitution of manganese by trivalent and tetravalent elements in the CMR perovskites Pr1-x(Ca, Sr)xMnO3 , 1996 .

[19]  Hwang,et al.  Lattice effects on the magnetoresistance in doped LaMnO3. , 1995, Physical review letters.

[20]  R. Fleming,et al.  Very large magnetoresistance in perovskite‐like La‐Ca‐Mn‐O thin films , 1994 .

[21]  Schultz,et al.  Giant negative magnetoresistance in perovskitelike La2/3Ba1/3MnOx ferromagnetic films. , 1993, Physical review letters.